(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "Mineral land classification : aggregate materials in the San Francisco-Monterey Bay area"

Digitized by the Internet Archive 

in 2013 



http://archive.org/details/minerallandclass01stin 



-.3 



™ wt sews 

UC DAVIS 



MINERAL LAND CLASSIFICAT 
AGGREGATE MATERIALS 

IN THE 
SAN FRANCISCO-MONTEREY BAY AREA 



1987 



CALIFORNIA DEPARTMENT OF CONSERVATION 
DIVISION OF MINES AND GEOLOGY 




SPECIAL REPORT 146 
Part III 

Classification of 
Aggregate Resource Areas 

NORTH SAN FRANCISCO BAY 
PRODUCTION-CONSUMPTION REGION 



THE RESOURCES AGENCY 

GORDON K. VAN VLECK 
SECRETARY FOR RESOURCES 



STATE OF CALIFORNIA 

GEORGE DEUKMEJIAN 
GOVERNOR 



UNIVERSITY OF CALIFORNIA 
DAVIS 

APR 2 9 1988 



DEPARTME MT OF C0*S*fcV J9BBBB. 

RANCft QWTWJPOC S. - LIBRARY 
DIRECTOR AW 




DIVISION OF MINES AND GEOLOGY 

JAMES F. DAVIS 
STATE GEOLOGIST 



SPECIAL REPORT 146 



MINERAL LAND CLASSIFICATION: 

AGGREGATE MATERIALS IN THE 

SAN FRANCISCO-MONTEREY BAY AREA 

PART III 



Classification of Aggregate Resource Areas 
North San Francisco Bay Production-Consumption Region 



By 

Melvin C. Stinson 

Michael W. Manson 

John J. Plappert 

Assisted by 

E. Leivas 

Ralph C. Loyd 

Russell V. Miller 

Michael A. Silva 



Under the Direction of 
James F. Davis, Rudolph G. Strand, and David J. Beeby 

1987 



CALIFORNIA DEPARTMENT OF CONSERVATION 

DIVISION OF MINES AND GEOLOGY 

1416 Ninth Street, Room 1341 

Sacramento, CA 95814 



FOREWORD 



Special Report 146, "Mineral Land Classification of the San Francisco-Monterey Bay Area," is 
the first analysis of mineral resources in the San Francisco-Monterey Bay area to be developed by 
the California Department of Conservation's Division of Mines and Geology under the authority of 
the Surface Mining and Reclamation Act of 1975 (SMARA) . This classification is provided to the State 
Mining and Geology Board for transmittal to the local governments which regulate land use in this 
region, and for consideration of areas, if any, to be designated as regionally significant. SMARA was 
enacted by the State Legislature to assure mineral resource conservation and adequate mined land 
reclamation. 

The Mining and Geology Board adopted Guidelines in June 1978 to be employed by the Division 
in its mineral resource classification. This report was prepared in conformance with those directives. 
The undertaking is of great importance in economic geology, because it deals with very specific mineral 
resource conservation issues in areas of intensive competing land use. 



State Geologist 
James F. Davis 



iii 



PREFACE 



Data presented in this report is accurate as of January 1983, at which time a preprint version 
of the report was circulated to lead agencies and made available to the public. Changes in reserves 
resulting from either the premature closure of mines active in 1983, or the permitting of new mines 
since that time, may have impacted forecasted depletion dates for the three production-consumption 
regions studied. However, the material presented and the fundamental conclusions of the report remain 
valid and useful. 



David J. Beeby 
Urban SMARA Program Manager 



CONTENTS 

Page 

FOREWORD iii 

PREFACE v 

EXECUTIVE SUMMARY (Part III) xi 

INTRODUCTION 1 

ESTABLISHMENT OF MINERAL RESOURCE ZONES 1 

Areas Classified MRZ-1 2 

Areas Classified MRZ-2 2 

Areas Classified MRZ-3 3 

Areas Classified MRZ-4 3 

Areas Classified SZ 3 

RING MOUNTAIN SCIENTIFIC RESOURCE ZONE 5 

EVALUATION OF AGGREGATE RESOURCES IN THE NORTH 

SAN FRANCISCO BAY P-C REGION 8 

Data Base 8 

Factors Considered in Calculation of Resources 8 

ESTIMATED AGGREGATE RESOURCES OF THE NORTH 

SAN FRANCISCO BAY PC REGION 9 

Sand and Gravel Resources 9 

Crushed Stone Resources 14 

Resource Sectors Outside of the Urbanizing Areas 18 

Resource Sectors Within Parks 20 

ESTIMATED 50-YEAR CONSUMPTION OF AGGREGATE 

Population Records 21 

Per Capita Consumption Rates 22 

Factors Affecting Per Capita Consumption Rates 22 

ALTERNATIVE SOURCES OF AGGREGATE 

Additional Crushed Stone Resources — North San Francisco Bay P-C Region 23 

Marine Sand and Gravel Deposits of the San Francisco Bay Area 23 

AGGREGATE RESOURCES OF ADJACENT P-C REGIONS 23 

Resource Estimates 23 

Estimated Consumption of Aggregate 33 

Deep Sand and Gravel Deposits Within the Livermore 

Valley-Sunol Valley — Niles Cone Production District 33 

Potential Aggregate Resources Outside of OPR Boundaries 33 

Sand and Gravel Resources 33 

Crushed Stone Resources 33 

CONCLUSIONS 35 

Alternatives 35 

Permit Expansion of Existing Gravel Pits and Quarries 35 

Permit Mining in Previously Unmined Sectors 35 

Encourage Exploration and Development of MRZ-3 Deposits 35 

Rely Upon Imports of Aggregate from Outside of the P-C Region 35 

ACKNOWLEDGMENTS 37 

REFERENCES 37 

APPENDIX A — Principles of the Mineral Classification System of the U.S. Bureau of Mines 

and the U.S. Geological Survey 39 

APPENDIX B — Summary of the Classification of MRZ-3 Areas, Construction Materials Only 49 



VII 



FIGURES 

Figure 3.1 Map of the southwestern corner of (Plate 3.14), the San Quentin Quadrangle, showing the 

location of the Ring Mountain Scientific Resource Zone 5 

Figure 3.2 Geologic map of the Ring Mountain Scientific Resource Zone 6 

Figure 3.3 Map of the North San Francisco Bay PC Region showing the location of the Russian 

River and Dry Creek sand and gravel production areas (Sectors A and B) 11 

Figure 3.4 North San Francisco Bay P-C Region: population and aggregate consumption 

records for years 1953-80 22 

Figure 3.5 North San Francisco Bay PC Region: sand and gravel, stone, and total 

aggregate consumption records for years 1953-80 24 

Figure 3.6 South San Francisco Bay P-C Region: population and aggregate consumption 

records for years 1953-80 24 

Figure 3.7 South San Francisco Bay P-C Region: sand and gravel, stone, and total 

aggregate consumption records for years 1953-80 25 

Figure 3.8 Monterey Bay P-C Region: population and aggregate consumption records for years 1953-80 25 

Figure 3.9 Monterey Bay P-C Region: sand and gravel, stone, and total aggregate 

consumption records for years 1953-80 26 

Figure 3.10 Annual per capita consumption of aggregate in the North San Francisco Bay, 

South San Francisco Bay, and Monterey Bay P-C regions for years 1954-79 26 

Figure 3.11 Projected populations of the North San Francisco Bay, South San Francisco Bay, 

and Monterey Bay P-C regions to the year 2030 27 

Figure 3.12 Marine sand and gravel deposits in San Francisco Bay and Sacramento River — Delta 29 



TABLES 

Table 3.1 List of U.S. Geological Survey 7.5-minute and 15-minute quadrangles classified 

in the North San Francisco Bay P-C Region 4 

Table 3.2 List of possible lead agencies (county and incorporated city governments) 

and other affected agencies (special districts, State, and U.S. government agencies) 

located within the North San Francisco Bay P-C Region 4 

Table 3.3 Geologic units underlying resource sectors within the North San Francisco Bay P-C Region 3 

Table 3.4 Geologic units underlying areas classified MRZ-3 within the 

North San Francisco Bay P-C Region 5 

Table 3.5 Resource sectors in the North San Francisco Bay P-C Region 9 

Table 3.6 Reserves and resources within sectors in the North San Francisco Bay P-C Region 10 

Table 3.7 Sectors that contain proven P.C.C.-grade aggregate, their resources, and any 

reserves that may exist within their boundaries 1 1 

Table 3.8 Percentage of total aggregate consumed, used for Portland cement concrete 

aggregate in the North San Francisco Bay P-C Region during the period 1953-1977 21 

Table 3.9 Population, aggregate production, and per capita consumption of aggregate 

in the North San Francisco Bay P-C Region during the period 1953-1980 23 

Table 3.10 Population projections, Marin, Napa, Western Solano, and Sonoma counties, 1980-2030 27 

Table 3.11 Projected aggregate consumption for the North San Francisco Bay P-C Region, 1981-2030 28 

Table 3.12 Marine sand resources of the San Francisco Bay area 28 

Table 3.13 Reserves and resources within sectors in the South San Francisco Bay P-C Region 30 

Table 3.14 Reserves and resources within sectors in the Monterey Bay P-C Region 32 

Table 3.15 Projected aggregate consumption to the year 2030 for the South San Francisco Bay, 

North San Francisco Bay, and Monterey Bay P-C regions 34 



viii 



PLATES 



Plate 3.1 Mineral Resource Zones and Resource Sectors — Marin County, North San Francisco Bay Production- 

Consumption Region 

Plate 3.2 Mineral Resource Zones and Resource Sectors — Napa and Western Solano counties, North San Francisco 

Bay Production-Consumption Region 

Plate 3.3 Mineral Resource Zones and Resource Sectors — Sonoma County, North San Francisco Bay Production- 

Consumption Region 

Plate 3.4 Generalized Geologic Map of 4 -County North San Francisco Bay Production-Consumption Region 



MINERAL LAND CLASSIFICATION MAPS 



Plate 3.5 Bolinas Quadrangle 

Plate 3.6 Camp Meeker Quadrangle 

Plate 3.7 Inverness Quadrangle 

Plate 3.8 Novato Quadrangle 

Plate 3.9 Petaluma Point Quadrangle 

Plate 3.10 Petaluma River Quadrangle 

Plate 3.11 Point Bonita Quadrangle 

Plate 3.12 San Francisco North Quadrangle 

Plate 3.13 San Geronimo Quadrangle 

Plate 3.14 San Quentin Quadrangle 

Plate 3.15 San Rafael Quadrangle 

Plate 3.16 Cordelia Quadrangle 

Plate 3.17 Cuttings Wharf Quadrangle 

Plate 3.18 Mount George Quadrangle 

Plate 3.19 Napa Quadrangle 

Plate 3.20 Benicia Quadrangle 

Plate 3.21 Fairfield South Quadrangle 

Plate 3.22 Mare Island Quadrangle 

Plate 3.23 Port Chicago Quadrangle 



Plate 3.24 


Bodega Head Quadrangle 


Plate 3.25 


Cotati Quadrangle 


Plate 3.26 


Duncan Mills Quadrangle 


Plate 3.27 


Glen Ellen Quadrangle 


Plate 3.28 


Kenwood Quadrangle 


Plate 3.29 


Petaluma Quadrangle 


Plate 3.30 


Santa Rosa Quadrangle 


Plate 3.31 


Sears Point Quadrangle 


Plate 3.32 


Sebastopol Quadrangle 


Plate 3.33 


Sonoma Quadrangle 


Plate 3.34 


Stewarts Point Quadrangle 


Plate 3.35 


Two Rock Quadrangle 


Plate 3.36 


Asti Quadrangle 


Plate 3.37 


Cloverdale Quadrangle 


Plate 3.38 


Geyserville Quadrangle 


Plate 3.39 


Guerneville Quadrangle 


Plate 3.40 


Healdsburg Quadrangle 


Plate 3.41 


Jimtown Quadrangle 


Plate 3.41a 


Mark West Springs Quadrangle 



RESOURCE SECTOR MAPS 



Plate 3.42 Asti Quadrangle 

Plate 3.43 Cloverdale Quadrangle 

Plate 3.44 Geyserville Quadrangle 

Plate 3.45 Jimtown Quadrangle 

Plate 3.46 Guerneville Quadrangle 

Plate 3.47 Healdsburg Quadrangle 

Plate 3.48 Glen Ellen Quadrangle 

Plate 3.49 Sears Point Quadrangle 

Plate 3.50 Sonoma Quadrangle 

Plate 3.51 Novato Quadrangle 

Plate 3.52 Petaluma River Quadrangle 

Plate 3.53 Cotati Quadrangle 



Sector A 


Plate 3.54 


Sector A 


Plate 3.55 


Sectors A,B 


Plate 3.56 


Sector A 


Plate 3.57 


Sectors B, Y 


Plate 3.58 


Sector B 


Plate 3.59 


Sectors C,K 


Plate 3.60 


Sectors C,X 


Plate 3.61 


Sectors C,K 




Sector D 


Plate 3.62 


Sectors D,E,J, 


Plate 3.63 


M,R,S,V 


Plate 3.64 


Sector F- 


Plate 3.65 



Benicia Quadrangle Sector G 

Cuttings Wharf Quadrangle Sector H 

Mount George Quadrangle Sector H 

Napa Quadrangle Sector H 

San Quentin Quadrangle Sector I 

Kenwood Quadrangle Sector K 

Inverness Quadrangle Sector L 

Camp Meeker Quadrangle Sectors N, 

o,p 

Bodega Head Quadrangle Sector Q 

Duncans Mills Quadrangle Sector T 

Stewarts Point Quadrangle Sector U 

Mark West Springs Quadrangle Sector W 



IX 



EXECUTIVE SUMMARY 
(PART III) 

The San Francisco-Monterey Bay area, with its population of over six million people, is the largest urbanized area 
in northern California. This region includes twelve counties that border on San Francisco or Monterey bays. Although 
substantial portions of the region have been developed, urbanization is still occurring at a rapid rate. 

In any urban development it is important that land-use decisions are made with full recognition of the natural resources 
of the area. Mineral resources, including aggregate, are limited within a given region. The object of this report is to convey 
information concerning the aggregate resources of the region and the expected needs of the region for such resources 
in the coming decades. For many years, the San Francisco-Monterey Bay area has been fortunate because adequate 
quantities of low-cost aggregate materials have been available locally. However, as more and more areas become 
urbanized, suitable sand, gravel, and stone deposits are being lost through urban development and are being diminished 
yearly by mining. 

The principal objective of this project is to classify land in the San Francisco-Monterey Bay area into Mineral Resource 
Zones (MRZs) based on guidelines adopted by the California State Mining and Geology Board. This classification project 
will assist the Board in designating lands that contain valuable mineral resources, as mandated by the Surface Mining and 
Reclamation Act of 1975. The objective of the classification and designation process is to insure through appropriate lead 
agency policies and procedures that mineral deposits of statewide or regional significance are considered for availability 
when needed. 

The Division of Mines and Geology has classified urbanizing lands within the North San Francisco Bay Production- 
Consumption (P-C) Region according to the presence or absence of significant sand, gravel, or stone deposits that are 
suitable as sources of aggregate. If a deposit contained more than $ 5 million worth of material suitable for at least 
subbase aggregate, the deposit was classified MRZ-2. In the San Francisco-Monterey Bay area, classification was done 
with regard to the suitability of the underlying material for use as asphaltic concrete aggregate, road base, or subbase 
material, in addition to its use as Portland cement concrete (P.C.C.) aggregate. This classification project stands in contrast 
to the various P-C region studies underway in southern California, where only P.C.C. -grade deposits were classified. This 
different approach is appropriate in the San Francisco-Monterey Bay area for two reasons: 

1. In the Los Angeles Basin almost all aggregate production is from deposits which meet P.C.C. specifications. 
The Bay area, in contrast, is not blessed with such large amounts of high quality sand and gravel and about 
half the production comes from deposits which are not of P.C.C. quality. To accommodate this difference, all 
deposits in the Bay area containing suitable material for aggregate commodities higher than fill quality have 
been classified. Each deposit has been identified on the basis of sales records or test data as to its highest 
use. 

2. The Los Angeles Basin aggregate production is dominated by alluvial sand and gravel deposits with very little 
crushed stone production. The Bay area is much more dependent on crushed stone quarries (many of which 
do not meet P.C.C. specifications) to satisfy its aggregate demands. Therefore, crushed stone deposits have 
been segregated from sand and gravel deposits in the San Francisco reports. 

The land classification within the North San Francisco Bay P-C Region is presented in the form of Mineral Resource 
Zones on 38 U.S. Geological Survey topographic quadrangles that accompany this report (Plates 3.5— 3.41a). Mineral 
resource zones were established on the basis of a sand, gravel, and stone resource appraisal which included the following 
actions: a study of pertinent geologic reports and maps; field investigations and sampling at outcrops and active and 
inactive pits and quarries; and an analysis of water-well logs and drill records. Twenty-five areas were determined to 
contain significant aggregate deposits and were classified MRZ-2. In addition, there were 112 areas that contained mineral 
resources, but their significance could not be evaluated from available data; these areas were classified MRZ-3. 

In order to organize the volume calculations of the aggregate resources, the State Geologist has utilized the concept 
of "sectors" to identify those MRZ-2 areas that have not been urbanized. The geometrical configuration of the deposit in 
each sector is fairly uniform, so that tonnage of the mineral resource present can be calculated with some reliability. Thus, 
for example, sector boundaries would be established between that part of a natural deposit formed on a fan, and that 
part within the confines of an adjacent modern stream channel and its floodplain. The sector concept is used for the 
convenience of arraying resource information, and is intended to convey accurate information regarding the locations 
and approximate tonnage of resources found in nonurbanized areas. 

In the North San Francisco Bay P-C Region, 25 MRZ-2 areas with existing land uses that are compatible with mining 
qualify as sectors; they contain a total of 2.4 billion tons of resources. The sectors are described in detail in this report, and 
are shown on Plates 3.42—3.65. One sector encompasses the unimproved portions of a dedicated park. It is recognized 
that dedicated parklands have special status as opposed to other current uses of sectorized land, consequently the resources 
within parks have been sectorized separately and the quantifications of those resources are presented separately in the 
tables. The quantification of resources within park sectors is expressed to a lower degree of accuracy rather than the higher 
level of accuracy reflected in the resource calculations for other sectors. 

The North San Francisco Bay P-C Region is dependent upon aggregate from both crushed stone and alluvial deposits. 
Because these two commodities are not entirely interchangeable, resource and reserve totals for each type have been 
identified separately. 

xi 



Reserves are aggregate materials that a company owns or controls, and for which it has a valid mining permit; 
resources are the total amount of available aggregate within the sector, including any reserves. The estimated resources 
within the 6 sand and gravel sectors amount to 908 million tons, of which 108 million tons are classified as reserves available 
for mining as of the end of 1980. The estimated crushed stone resources within the remaining 19 sectors amount to 1.4 
billion tons, of which 432 million tons are classified as reserves available for mining as of the end of 1980. 

The total projected aggregate consumption through the year 2030 is estimated to be 478 million tons, of which at 
least 24 percent (115 million tons) must be of P.C.C. quality. Of the projected total demand, 540 million tons (113 percent) 
were available for mining at the end of 1980. Unless additional resources are permitted for mining or alternative resources 
are utilized, existing reserves will be depleted in 49 years (2036). To make the projections, production records and 
population figures were correlated for the past 28 years (1953-1980) to obtain an average per capita rate. The derived 
rate of 8.8 tons per year was used along with population projections to make the estimate of total consumption. 

The average annual per capita consumption rate for the North San Francisco Bay P-C Region may decrease, at a 
more or less steady rate, as the area becomes more urbanized until a steady state (urban maturity) is reached. Should 
unforeseen events occur, such as massive urban renewal, disaster reconstruction, or major recession, the per capita 
consumption rate could change significantly. The presence of several major active fault systems within the North San 
Francisco Bay P-C Region increases the chance for a damaging earthquake and the need for subsequent extensive 
reconstruction afterwards. 

Alternative sources of aggregate, in addition to those deposits classified MRZ-2 and MRZ-3, occur in areas within 
the North San Francisco Bay P-C Region, and in adjacent P-C regions. Some potential deposits lie outside the OPR 
urbanizing boundaries, but still within the P-C region boundaries. Included within the group of potential resources are the 
extensions of several deposits classified MRZ-2 or MRZ-3. In addition, sand and fine gravel occur in bars on the floor of 
San Francisco Bay between the Golden Gate Bar and the confluence of the Sacramento and San Joaquin rivers. Except 
for the aggregate resources in adjacent P-C regions and marine sand deposits, too little is known about the physical and 
chemical qualities of most of the alternative sources to permit even crude resource estimates. 

If additional aggregate is needed in the North San Francisco Bay P-C Region on a short-term basis, the most readily 
available material is located in the neighboring regions — South San Francisco Bay, Monterey Bay, and Sacramento- 
Fairfield P-C regions. On a short-term basis the active producers in these P-C regions can send large amounts of aggregate 
into the North San Francisco Bay P-C Region, but the delivered price per ton would be greatly increased by inflated 
transportation costs and by any supply-demand conflicts. The long-term (50-year) resource picture is more uncertain. The 
South San Francisco Bay P-C Region is projected to have a substantial deficit of aggregate, while the Monterey Bay P-C 
Region appears to have a surplus of material. Projected aggregate needs and available supplies in the Sacramento- 
Fairfield P-C Region are currently being studied. 

As with many forecasts of economic activity, the forecasts in this report should not be viewed as offering unqualified 
predictions of how the future will unfold. The forecasts of this report are based upon assumptions concerning the accuracy 
of the basic data, and the continuation of the development trends of the past three decades into the five decades ahead. 

Assuming, however, the correctness of our forecasts for the consumption of aggregate, the following conclusions 
were reached: 

• The anticipated consumption of aggregate resources in the P-C region to the year 2030 is forecast to be 478 million tons, of 
which approximately 24 percent or 115 million tons must be of P.C.C. quality. 

• Unless additional resources are permitted for mining, or alternative resources are utilized, total existing reserves (both P.C.C. and 
non-P.C.C aggregate) would be depleted within 49 years (2036). About 540 million tons of permitted aggregate reserves exist 
in the P-C region. About 20 percent of the permitted reserves are sand and gravel, and 80 percent are crushed stone. In total, 
the 540 million tons amount to 113 percent of the anticipated consumption during the next 50 years. 

• Of the 540 million tons of permitted reserves, about 100 million tons are suitable for use as P.C.C. aggregate. This amounts to 
97 percent of the anticipated consumption during the next 50 years. 

• The expected longevity of the existing reserves is based upon the assumption that mining of these reserves will continue to be 
permitted until the reserves are depleted. 

• P.C.C. reserves, because of their higher quality specifications will be the most difficult to replace as existing permitted deposits 
are depleted. 

• Of 15 stratigrophic/lithologic units suitable for aggregate in the P-C region, only 4 are suitable for P.C.C. aggregate. Only two 
of these units (Quaternary Alluvium and Novato Conglomerate) are sources of sand and gravel. This contrasts markedly with 
other P-C regions examined to date, where P.C.C. sand and gravel can be extracted from several older sedimentary formations 
as well as from modern stream deposits. 

• A total of 2.4 billion tons of aggregate resources (including reserves) have been identified within the North San Francisco Bay 
P-C Region. Of this total, 31 million tons are on parklands. Nine-tenths of a billion tons of sand and gravel and 1.4 billion tons of 
crushed stone compose the 2.4 billion tons of resources. 

• If all of the reserves suitable for P.C.C. aggregate are utilized only for that purpose, P.C.C. -grade reserves would be depleted in 
about 45 years. However, we can expect that some of the production from these reserves will be used for non-P.C.C. applications, 
consequently, the expected exhaustion of these reserves will occur considerably earlier. 

• Most of the high quality P.C.C. resources are present in two sectors in the Russian River area. These also constitute the main 
source of sand and gravel in the P-C region. These two sectors contain 21 parcels that contain a total of about 854 million tons 
of sand and gravel resources. 

• Of 34 aggregate production sites in the North San Francisco Bay P-C Region. 14 contain sand and grovel resources and 
20 contain crushed-stone resources. 



XII 



SPECIAL REPORT 146 

MINERAL LAND CLASSIFICATION: 
AGGREGATE MATERIALS IN 
THE SAN FRANCISCO-MONTEREY BAY AREA 



Part 



Classification Of Aggregate Resource Areas 
North San Francisco Bay Production-Consumption Region 



INTRODUCTION 

The Division of Mines and Geology (DMG) has classified 
urbanizing lands within the North San Francisco Bay Produc- 
tion-Consumption (P-C) Region according to the presence or 
absence of significant sand, gravel, or stone deposits that are 
suitable as sources of aggregate. The land classification is pre- 
sented in the form of Mineral Resource Zones (MRZs)— as de- 
scribed in Part I of this report — on 38 U.S. Geological Sur- 
vey topographic quadrangles that accompany this report 
(Plates 3.5-3.41a). Twenty-five areas are classified MRZ-2 
(they contain significant aggregate deposits). Twenty-five re- 
source sectors containing a total of 2.4 billion tons of resources 
have been identified within the MRZ-2 areas. The sectors are 
described in detail in this report, and are shown on 24 additional 
topographic quadrangles. 

Based on population records and projections and aggregate 
production records, the North San Francisco Bay P-C Region 
will need 478 million tons of aggregate during the next 50 years. 
Of this projected demand, 540 million tons (113 percent) were 
available for mining at the end of 1980. 

Several alternative sources of aggregate for this P-C region 
are discussed. Similar studies have been completed for the South 
San Francisco Bay and Monterey Bay P-C regions (Parts II and 
IV) and pertinent data are included herein for comparison. 

To assist the reader, the following "road map" through this 
report will be helpful. The classification process, which is de- 
scribed more fully in Special Report 146, Part I, occurs in seven 
separate but interrelated steps. Steps 1 and 2 in the follow- 
ing list are described in Part I, but are restated merely for com- 
pleteness. Steps 3 through 7 form the bulk of this report 
(Part III) and are described sequentially. Resource information 
is integrated in Table 3.6 and described on a sector-by-sector 
basis on pages 10 through 21. 

These are the steps: 

1. Determination of Production — Consumption (P-C) 
Region Boundaries: In this step, active aggregate opera- 
tions are identified (Production) and the market area 
they serve is determined (Consumption). 

2. Determination of Modified OPR Boundaries Within the 
P-C Region: Only those portions of the P-C Region that 
are urbanized or urbanizing (based on determination 
by the State Office of Planning and Research, as modi- 
fied by local lead agencies) are classified for their aggre- 
gate content. Other areas may be classified with the 
approval of the State Mining and Geology Board 
(SMGB). This step determines which areas should be 
classified. 



3. Estabiishment of Mineral Resource Zones (MRZs): 
This step includes a geologic appraisal for aggregate 
deposits of all land within the modified OPR bounda- 
ries. 

4. Determination of Sectors: Only those portions of land 
classified MRZ-2 (in Step 3) that have current land 
uses considered to be compatible with mining are con- 
sidered to be available as future resources for the P-C 
region. This step utilizes intensive field checking to 
make that determination. 

5. Calculation of Resource Volumes Within Sectors: In 
this step, careful analysis of site-specific conditions is 
utilized to calculate total volumes of aggregate reserves 
and resources within each sector. 

6. Forecasting: In this step, anticipated aggregate demand 
in the P-C region for the next 50 years is determined. 
This is done by correlating historic population and ag- 
gregate production data for the past 28 years to calcu- 
late an annual per capita consumption rate. This figure 
is used with projected population figures in the area to 
determine anticipated aggregate demand. Results of 
this analysis are compared with total volumes of per- 
mitted aggregate reserves in the P-C region. 

7. Alternative Resources: A variety of potential alterna- 
tive sources of aggregate are evaluated in this final step 
of the classification process. 



ESTABLISHMENT OF 
MINERAL RESOURCE ZONES 

Mineral resource zones within the North San Francisco Bay 
P-C Region were established on the basis of a sand, gravel, and 
stone resource appraisal which included the following actions: a 
study of pertinent geologic reports and maps; field investigations 
and sampling at outcrops and active and inactive pits and quar- 
ries; analysis of water -well logs and drill records. Twenty-five 
areas were classified MRZ-2 (see below for a description of 
MRZ terminology). In addition, there were 1 12 areas that con- 
tained mineral resources, but did not possess all the qualifica- 
tions for classification as MRZ-2; these areas were classified 
MRZ-3. 

Due to the large amount of area classified in this report — 
portions of 38 quadrangles — the field and office work extended 
over a 4-year period. Field work was done during the following 



DIVISION OF MINES AND GEOLOGY 



SR 146 



months: Marin County — August 1980, October 1980; Napa 
County — May 1980, August 1980; Sonoma County — February 
1980, August 1980, May 1981; Solano County— August 1980. 
Selected areas within these counties were revisited in August 
1982, May 1983. and October 1984. 

Plates 3. 5-3. 41a are 148,000 scale copies of U.S. Geological 
Survey 7.5 -minute topographic quadrangles that cover the 
urbanizing portions of the North San Francisco P-C Region. 
Refer to Plate 1.1 (in Part I) or Table 3.1 for an index to 
quadrangles classified in the P-C region. A list of possible 
lead agencies and other affected agencies within the P-C region 
is presented in Table 3.2. 

Areas Classified MRZ-1 

Areas classified MRZ-1 are "areas where adequate informa- 
tion indicates that no significant mineral deposits are present, or 
where it is judged that little likelihood exists for their presence" 
(see Part I, Appendix A-3, page 25). The areas in the North San 
Francisco Bay P-C Region that have been classified MRZ-1 are 
underlain by Quaternary alluvial material judged to contain too 
much clay and silt for use as aggregate. The data used in evaluat- 
ing these areas included available water-well logs and the best- 
available geologic and soil maps. 

Areas Classified MRZ-2 

Twenty- five areas within the North San Francisco Bay P-C 
Region are classified MRZ-2 (Plates 3.1-3.3, and 3.5-3.41a). 
These are "areas where adequate information indicates that sig- 
nificant deposits are present, or where it is judged that a high 
likelihood for their presence exists" (see Part I, Appendix A-3, 
p. 25) 

The guidelines set forth two requirements to be used to 
determine if land should be classified MRZ-2: 

1. The deposit must be composed of material that is suita- 
ble as a marketable commodity. 

2. The deposit must meet threshold value. The projected 
value (gross selling price) of the deposit, based on the 
value of the first marketable product must be at least 
$5 million (1978 dollars). 
Although not specified in the guidelines, the following crite- 
ria were applied to each deposit to test its suitability for inclusion 
in a MRZ-2 zone: 

A. The presence of an operating quarry within the deposit 
is considered proof that condition 1 has been met. 

B. An average value of $2.00 per ton (all aggregate types) 
and a conversion factor of 2,500 tons per acre-foot of 
material (0.065 tons per cubic foot with 10 percent 
waste) requires a minimum amount of 1000 acre-feet 
of material within the deposit, exclusive of overburden 
and fill material, to meet suggested threshold value. 

C. A deposit of aggregate material must have an overbur- 
den-to-ore ratio of less than 1 to 1 in order for mining 
to be economic at the present time. 

Specific criteria are discussed in the section "Estimated 
Aggregate Resources of the North San Francisco Bay P-C Re- 
gion". 

In the San Francisco-Monterey Bay area, classification was 
done with regard to the suitability of the underlying material for 
use as asphaltic concrete aggregate, roadbase, or subbase materi- 



al, in addition to its use as Portland cement concrete (P.C.C) 
aggregate. If a deposit contained more than $ 5 million 
worth of material suitable for at least subbase aggregate, the 
deposit was classified MRZ-2. This classification project stands 
in contrast to the various P-C region studies underway in south- 
ern California, where only the P.C.C. -grade deposits were classi- 
fied. This different approach is appropriate in the San 
Francisco-Monterey Bay area for two reasons: 

1. In the Los Angeles Basin almost all aggregate produc- 
tion is from deposits which meet P.C.C. specifications. 
The Bay area, in contrast, is not blessed with such large 
amounts of high quality sand and gravel, and about half 
the production comes from deposits which are not of 
P.C.C. quality. To accommodate this difference, all 
deposits in the Bay area containing suitable material for 
aggregate commodities higher than fill quality have 
been classified. Each deposit has been identified on the 
basis of sales records or test data as to its highest use. 

2. The Los Angeles Basin aggregate production is domi- 
nated by alluvial sand and gravel deposits with very 
little crushed stone production. The Bay area is much 
more dependent on crushed stone quarries (many of 
which do not meet P.C.C. specifications) to satisfy its 
aggregate demands. Therefore, crushed stone deposits 
have been segregated from sand and gravel deposits in 
the San Francisco reports. 

Only two sand and gravel deposits are within the OPR areas 
of the North San Francisco Bay P-C Region. The stream channel 
of Sonoma Creek between Glen Ellen and Schellville (Sonoma 
County) is classified MRZ-2. Near Black Point in Marin Coun- 
ty, portions of the Novato Conglomerate have been classified 
MRZ-2. However, approximately 90 percent of this deposit un- 
derlies already urbanized land. Such areas are considered una- 
vailable as sources for aggregate because they occur in areas 
presently committed to uses that preclude the extraction of ag- 
gregate (see "Calculation of Available Resources" in Part I, p. 
9). 

Nineteen areas within the North San Francisco Bay P-C 
Region have been classified MRZ-2 due to the presence of large 
amounts of stone suitable for use as crushed stone. In Marin 
County, Sonoma Volcanics and Franciscan Complex sandstone 
(graywacke), and greenstone are the principle rock types. Green- 
stone and graywacke of the Franciscan Complex form the depos- 
it classified MRZ-2 in western Solano County at Sulphur Springs 
Mountain. An active quarry is located in the only MRZ-2 depos- 
it in Napa County. This deposit consists of basalt, rhyolite, and 
tuff of the Sonoma Volcanics, and extends into portions of four 
quadrangles. Twelve rock deposits are classified MRZ-2 in So- 
noma County. At Petaluma a large deposit of Sonoma Volcanics 
basalt is quarried for asphaltic concrete aggregate, and a smaller 
deposit of Franciscan Complex rocks is quarried for roadbase 
aggregate. West of Healdsburg, greenstone of the Franciscan 
complex is mined for roadbase. Basalt, tuff, and related sedimen- 
tary rocks of the Sonoma Volcanics, in addition to sand and 
pebbly sand of the Petaluma Formation, are quarried for sub- 
base, drain rock, and fill material near Stony Point, Petaluma, 
and north of Sears Point. Near Glen Ellen, rhyolite and tuff of 
the Sonoma Volcanics are quarried for subbase, drain rock, and 
fill material. Also near Glen Ellen, rhyolite and tuff of the So- 
noma Volcanics are quarried for flagstone and roadbase. East of 
Mark West Springs, pillow basalt of the Franciscan complex is 
quarried for roadbase and fill. Some of these areas are unavaila- 
ble for mining, because they occur in areas presently urbanized 
or committed to uses that preclude the extraction of aggregate. 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



Table 3. 1 List of U.S. Geological Survey 7.5-minute and 15-minute quadrangles classified in the North San Francisco Bay P-C 
Region. Plates 3.5-3.41 a show the classification in these quadrangles. 



MARIN COUNTY 


PI 


.ATI 


Bolinas 


3. 


.5 


Inverness 


3. 


.7 


Novato 


3. 


.8 


Petaluma Point 


3. 


.9 


Petaluma River 


3. 


.10 


Point Bonita 


3, 


.11 


San Francisco North 


3, 


.12 


San Geronimo 


3, 


.13 


San Quentin 


3, 


.14 


San Rafael 


3, 


.15 



WESTERN SOLANO COUNTY 



PLATE 



SONOMA COUNTY 



PLATE 



NAPA COUNTY 


PLATE 


Cordelia 


3.16 


Cuttings Wharf 


3.17 


Mount George 


3.18 


Napa 


3.19 



Benicia 


3, 


.20 


Cordelia 


3. 


.16 


Cuttings Wharf 


3. 


.17 


Fairfield South 


3, 


.21 


Mare Island 


3, 


.22 


Mount George 


3, 


.18 


Napa 


3. 


.19 


Port Chicago 


3. 


.23 



Asti 


3. 


.36 


Bodega Head 


3. 


,24 


Camp Meeker 


3. 


.6 


Cloverdale 


3. 


.37 


Cotati 


3. 


.25 


Duncan Mills 


3. 


,26 


Geyserville 


3. 


,38 


Glen Ellen 


3. 


,27 


Guerneville 


3. 


,39 


Healdsburg 


3. 


.40 


Jimtown 


3. 


,41 


Kenwood 


3. 


,28 


Mark West Springs 


3. 


.41a 


Petaluma 


3. 


,29 


Petaluma River 


3. 


.10 


Santa Rosa 


3. 


,30 


Sears Point 


3. 


.31 


Sebastopol 


3. 


,32 


Sonoma 


3. 


.33 


Stewarts Point 


3. 


.34 


Two Rock 


3. 


,35 



Table 3.2 List of lead agencies (county and incorporated city governments) and other affected agencies (special districts, 
State and U.S. Government agencies) located within the North San Francisco Bay PC Region. Agencies with active aggregate 
operations within their jurisdictional boundaries are denoted by asterisks (*) . Agencies that have land classified MRZ-2 within 
their jurisdiction are denoted by plus signs ( + ) . 



MARIN COUNTY 



NAPA COUNTY 



SOLANO COUNTY 



SONOMA COUNTY 



*+Marin County 
Belvedere 
Corte Madera 
Fairfax 
Larkspur 
Mill Valley 
Novato 
Ross 

San Anselmo 
San Rafael 
Sausalito 
Tiburon 

US Department of Defense 
US Department of the Interior 
US Army 
US Navy 

US Coast Guard 
State of California 
*Bay Conservation and 

Development Commission 



*+Napa County 
Calistoga 
Napa 

Saint Helena 
Yountville 
State of California 
*Bay Conservation and 

Development Commission 



*+Solano County 
Benicia 
Vallejo 
US Navy 

State of California 
* Bay Conservation and 

Development Commission 



*+Sonoma County 
*+Cloverdale 
Cotati 
+Healdsburg 
+Petaluma 
Rohnert Park 
Santa Rosa 
Sebastopol 
+Sonoma 

State of California 
*Bay Conservation and 

Development Commission 



DIVISION OF MINES AND GEOLOGY 



SR 146 



The other MRZ-2 areas that lie outside of the OPR urbaniz- 
ing boundaries are located in four areas of Sonoma County. 
Along the Russian River from north of Cloverdale to the vicinity 
of the Wohler Bridge, near Mirabel Heights and along the lower 
1 5 miles of Dry Creek are extensive deposits of sand and gravel 
which supply the high quality aggregate for most of the North 
San Francisco Bay P-C Region. Two smaller stream deposits of 
sand and gravel are found in Austin Creek and Gualala River, 
also in Sonoma County. 

As explained in Part I under the heading "Concept of Sec- 
tors", the State Geologist has identified as resource sectors those 
MRZ-2 areas with existing land uses that are compatible with 
mining (Part I, p. 9 and Appendix A-5, p. 41). In the North 
San Francisco Bay P-C Region, 25 areas qualify as sectors; they 
contain sand and gravel, or stone suitable for aggregate. Table 
3.3 lists the geologic units and formations underlying the re- 
source sectors, and shows which sectors contain material that 
may be suitable for Portland cement concrete aggregate. De- 
tailed descriptions of the individual sectors are included below 
in the section "Estimated Aggregate Resources of the North San 
Francisco Bay P-C Region". The identification of resource sec- 
tors has been done to inform lead agencies and others of re- 
sources that could be made available for mining by virtue of the 
present, generally undeveloped status of the land. It is recog- 
nized that dedicated parklands have special status as opposed to 
other current uses of sectorized land, consequently the resources 
within parks have been sectorized separately and the quantifica- 
tion of those resources are presented separately in the tables. The 
quantification of resources within park sectors are expressed to 
a lower degree of accuracy rather than to the higher level of 
accuracy reflected in the resource calculations for other sectors. 
The sectorization of any area is not an advocacy of mining in that 
area. 

Areas Classified MRZ-3 

One hundred twelve (112) areas in the North San Fran- 
cisco Bay P-C Region have been classified MRZ-3 (Plates 3.1- 

3.3, and 3.5-3.41). Areas classified MRZ-3 contain mineral 
deposits, but their significance cannot be evaluated from avail- 
able data (see Part I, Appendix A-3, p. 25). Geologic units and 
formations underlying areas classified MRZ-3 are given in Table 

3.4. A summary of MRZ-3 areas, by county and by quadrangle, 
is presented in Appendix B of this report (p. 49). 

MRZ-3 areas located in valleys are generally underlain by 
Quaternary alluvial deposits containing sand and gravel, but 
resource calculations cannot be made due to inadquate subsur- 
face data (either the well-log data is unavailable or the available 
data is inconclusive). An area will be classified MRZ-3 if, based 
upon well-log data, sand and gravel are present that do not meet 
the criteria for MRZ-2 listed above. MRZ-3 areas in hilly or 
mountainous terrain are generally underlain by Tertiary sedi- 
mentary or volcanic rocks, or by Mesozoic sedimentary, vol- 
canic, or metamorphic basement rocks. Many of these areas are 
classified as such due to the lack of outcrops or accessible areas 
for field examination. 

Areas Classified MRZ-4 

Areas where available information is inadequate for assign- 
ment to any other MRZ category are classified MRZ-4 (Part I, 
Appendix A-3, p. 25 ). In the North San Francisco Bay P-C 
Region, all MRZ-4 areas are located in hilly or mountainous 
terrain underlain by Tertiary-age sedimentary or volcanic rocks, 
or Jurassic-Cretaceous sedimentary, igneous, or metamorphic 



rocks. The areas often are poorly mapped, have poor accessibili- 
ty, and may be underlain by rock units that have never been 
quarried for aggregate. 

Areas Classified SZ 

In addition to Mineral Resource Zones, the State Mining 
and Geology Board has established Scientific Resource Zones 
(SZ, see Part I, Appendix A-3, p. 25). These are areas that 
contain unique or rare occurrences of rocks, minerals, or fossils 
of outstanding scientific significance. 

Such an area occurs on the northern end of Tiburon Penin- 
sula, within the OPR urbanizing boundaries. This area, known 
as the Ring Mountain area, is "an important and famous geologi- 
cal locality. The rare, colorful, and enigmatic metamorphic 
rocks that occur there have been studied by geologists and 
mineralogists for many decades, but their origins are still not 
fully understood. This area should be preserved in its present 
condition for further study and as a natural geologic exhibit" 
(Rice, Smith, and Strand, 1976, p. 5). 

The Ring Mountain area has been classified SZ, and a de- 
scription of the area is included with the present study. 



Table 3.3 Geologic units underlying resource sectors within 
the North San Francisco P-C Region. Those deposits chosen 
as sectors are identified by the letters A-Y. Present or poten- 
tial sources of Portland cement concrete aggregate are identi- 
fied with an asterisk (*). Geologic units shown without an 
asterisk are potential sources of non-P.C.C. aggregate. 



\ GEOLOGIC 
\ UNIT 

QUADRANGLE \^ 


11 

w > 


IU 

t- 
< 
cr 
uj 
2 
oo 

<i 

oo 

z o 


(A 

o 

z 
< 
oo 

81 

%->- 

5 co _j 
Ouj < 
z o w 
oz < 
to < a) 


< 
z 

IU 

it. 

< I 

10 (E 


a 
in 

< 
I 1 

CO w uj 

O-i V- 
7a.IL 
<5S 
COZ 
u. ^ 


1 z 

Ox° 

Z^ltl 
< > a) 

ex O cr 
U.OC3 


z|2 

lis 

u.oo) 


IU 

z 1- 
< z 

Oxc 

CO uj t 

OjJlU 
Z^D. 
<5tx 

CCOUJ 

u. O<o 


Asti 


A 
















Cloverdale 


A 
















Geyserville 


A B 
















Jimtown 


A B 
















Guerneville 


B 










Y 






Healdsburg 


B 
















Glen Ellen 


C 






K 










Sears Point 


C 




X 












Sonoma 


C 






K 










Novato 




D 














Petaluma River 




D 


EJSV 




R 








Cotati 






F 












Benicia 










G 


G 


G 




Cuttings Whart 






H 












Mount George 






H 












Napa 






H 












San Quentin 














1 




Kenwood 








K 










Inverness 










L 






M 


Camp Meeker 










NOP 








Bodega Head 














Q 




Duncans Mills 


T 












T 




Stewarts Point 


U 
















Mark West Springs 










W 









1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



^v Geologic 
N^ Unit 

Quadrangle \. 


*> e 


e ^ ~ 


E 3 1- 

c *-■ e 




E 


II 


jjj 


III 


2£X 


-o E 4i 


<o E a> 


C Q-O 


Z~- E 

«e2 


Bol inas 






















x 






Novato 




X 


















X 


X 




Petaluma Point 










X 














X 




Petal uma River 




X 
























Point Bonita 




















X 








San Francisco North 




















X 


X 




X 


San Gerommo 






















X 


X 




San Quentin 
























X 


X 


San Rafael 




















X 


X 


X 




Cordelia 




X 








X 




X 








X 




Cuttings wharf 




X 








X 


X 


X 












Mount George 




X 
























Napa 




X 


X 






X 
















Benicia 
























X 




Cotati 




X 
























Glen Ellen 




X 
























Kenwood 




X 




X 




















Petaluma 




X 
























Santa Rosa 


X 


X 
























Sebastopol 


















X 










Sonoma 


X 


X 




X 




















Two Rock 


















X 










Asti 


X 


























Cloverdale 


X 


























Geyserville 


X 


X 
























Guerneville 


X 


























Jimtown 


X 


X 


















X 






Healdsburg 


X 



























Table 3.4 Geologic units underlying areas 
classified MRZ-3 within the North San Fran- 
cisco Bay P-C Region. 



Figure 3.1 Map of the southwestern corner of Plate 
3.14, the San Quentin Quadrangle, showing the location 
of the Ring Mountain Scientific Resource Zone. 



RING MOUNTAIN SCIENTIFIC 
RESOURCE ZONE 

The Ring Mountain Scientific Resource Zone consists of 
approximately 190 acres of land on the north end of Tiburon 
Peninsula. Ring benchmark (Elevation 602 feet) lies near the 
east central edge of the area and is the highest point on Tiburon 
Peninsula. Figure 3.1 (the southwestern corner of the San Quen- 
tin Quadrangle, Plate 3.14) shows the location of the Ring 
Mountain Scientific Resource Zone. The detailed geology of the 
area is shown on Figure 3.2. 

The Ring Mountain area was mapped by Rice and Smith 
(1976, Plate IE) and described in an open-file report prepared 
in cooperation with Marin County and a number of cities and 
towns in southern Marin County (Rice, Smith, and Strand, 
1976, p. 50-53). The following description of the area is quoted 
from that report: 

In general, the Tiburon Peninsula appears to 
be made up of a series of superimposed, thrust-fault 
slices of diverse rock sequences, the youngest rocks 
at the bottom and the older ones above. 

Well-stratified sandstones and shales are ex- 
posed in many road cuts along Paradise Drive and 
Tiburon Boulevard northwest of their intersections 
with Trestle Glen Boulevard, and also in wave-cut 
cliffs along much of the northeast shore of the 
peninsula. As revealed in good exposures, se- 
quences of these sedimentary rocks range from 
predominantly sandstone in beds a few inches to a 




Base from U.S.G.S. San Quentin 7 1' 2 -Minute Quadrangle 



DIVISION OF MINES AND GEOLOGY 



SR 146 



12 2° 30' 
37°55' 




0.1 0.2 0.3 0.4 0.3 km 



Base from U.S.G.S. San Quentin 7 1/2-Minute Quadrangle 

Figure 3.2 Geologic map of the Ring Mountain Scientific Resource Zone. Geology and explanation from Rice and Smith, 1976, Plate IE. 

EXPLANATION 



fm = Franciscan Melange. A tectonic mixture consisting of 
small to large masses of resistant rock types, principally 
of sandstone, greenstone, chert, and serpentine, but in- 
cluding various exotic metamorphic rock types embedded 
in a matrix of pervasively sheared or pulverized rock 
material. Masses too small to delineate at map scale are 
indicated by the symbol "x". 

chl = Chlorite schist. A dull green schistose rock composed 
principally of chlorite, commonly containing veins of 
tremolite. 

gl = Metamorphic rock. Chiefly dense, coarsely crystalline, 
dark-bluish glaucophane-bearing schists or gneisses and 
dark-green eclogite. 

sp = Serpentine. Pale green to dark-green, fine-grained 
metamorphic rocks composed almost entirely of the mag- 
nesium silicate minerals lizardite and chrysotile. 
Is = Landslide 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



few feet thick, and with little or no shale, to alter- 
nating, graded, thin beds of sandstone and shale, 
each bed an inch to a few inches thick. Bedding is 
characteristically steeply dipping, and the graded 
beds commonly reveal tight, overturned folding. 
These are unmetamorphosed sedimentary rocks, 
formed from sand and mud deposited in a deep 
ocean environment, and probably of Late Creta- 
ceous age (about 80 million years). 

In contrast to these rocks that appear to consti- 
tute a base for the peninsula, much of the crest area 
is capped by large sheets of serpentine, a rock of 
igneous origin that almost certainly originated in 
the mantle of the earth, beneath the crust on which 
the sandstones and shales were deposited. Though 
the serpentine has not been dated, it is perhaps the 
oldest of the rock sequences on the peninsula, prob- 
ably more than 150 million years old. 

Northwest of Trestle Glen Boulevard, the 
sheets of serpentine that cap the two crests in the 
Ring Mountain area are separated from the under- 
lying sandstones and shales by a thick zone com- 
posed principally of intensely sheared Franciscan 
melange matrix. The melange represents an ancient 
fault zone, a clue to the mechanisms whereby the 
serpentine, from beneath the crust of the earth, was 
thrust over sedimentary rocks deposited on the sur- 
face of the crust. 

Scattered on the ridge in the Ring Mountain 
area, in places on the serpentine but for the most 
part downslope from it within melange and land- 
slide areas, are many prominent, dark-colored 
monuments and blocky masses of various unusual 
and weather-resistant metamorphic rock types that 
help make this area unique and famous as a geologic 
locality. Generally speaking, each of these mono- 
lithic masses has a different fabric and assemblage 
minerals than its nearest neighbors. Most of them 
are coarse-grained, massive to schistose rock types 
that include eclogites, hornblende-garnet amphibo- 
lites, glaucophane-garnet schists, stilpnomelane-rie- 
beckite-quartz schists, chlorite schists, and 
actinolite schists. Some are of such unusual mineral 
composition and massive texture that none of the 
standard rock names apply to them. The petrology 
and mineralogy of the metamorphic rocks in this 
area have been studied in considerable detail by 
Dudley (1967). 

These exotic metamorphic rock masses, rang- 
ing in size from less than a foot to many tens of feet, 
are or were embedded in the weak, sheared matrix 
of the melange or in the serpentine. Some have 
simply been partially exposed by erosion of the 
weak rock material that enclosed them, for they 
appear to be in place, partially embedded. Others 
have been left behind by erosion as loose rock 
masses on the surface, and many have been trans- 



ported downslope by landslides, in places as far as 
the bay. 

They are clearly isolated tectonic fragments, 
delivered from a disrupted source or sources un- 
known, but presumably at great depths as revealed 
by the presence in them of the mineral lawsonite, 
and transported to the present locality by the same 
thrust faulting mechanisms that brought the ser- 
pentine here. No coherent outcrop areas of such 
rocks are known anywhere on the surface of the 
earth. Their origins remain an enigma, even though 
studied over many decades by many geologists and 
mineralogists. 

Most, perhaps all, of the rare and unusual rock 
types found in this area have been found in similarly 
disrupted zones at one or more other localities in 
the world. To the best of our knowledge, however, 
the rich assortment of them in the Ring Mountain 
area is not duplicated anywhere else . . . 

This area caught the attention of many 
mineralogists in the 1890s, when a newly discovered 
mineral, named lawsonite, was first described 
(Ransome, 1895) from a large, picturesque outcrop 
of metamorphic rock that used to dominate the 
landscape where Reed Ranch Road presently ends. 
That outcrop was destroyed by blasting and bull- 
dozing in 1964 in preparation of a subdivision 
(Rice, 1964). 

Lawsonite was subsequently found to be one of 
the significant metamorphic indicator minerals, in- 
dicating that metamorphism (recrystallization of 
the rock) had occurred under conditions of great 
pressures (equivalent to as much as 20 miles of 
burial), but at relatively low temperatures (less 
than about 400 degrees centigrade, well below the 
melting point of the rock). 

Following the initial discovery of lawsonite, 
other relatively rare minerals and rock types were 
found in the vicinity of Ring Mountain (the local 
name for the northern crest area of Tiburon Penin- 
sula), and the area has been visited and studied by 
numerous geologists and mineralogists. 

As an interesting sidelight on these rocks, a few 
years ago the face of one of the large blocks of 
metamorphic rocks in the Ring Mountain area was 
found to have many ancient petroglyphs carved on 
it (Hotz and Clewlow, 1974), the first petroglyphs 
reported in the Bay area by archaeologists. The 
carvings are in chlorite schists, a very soft rock, but 
one with great resistance to weathering processes 
that decompose most common rock types. Since 
that discovery, many other petroglyphs have been 
found in the Ring Mountain area, all carved in 
similar chlorite schists. . . 

References named above are found in the Reference Section at 
the end of this report (p. 37 ). 



DIVISION OF MINES AND GEOLOGY 



SR 146 



EVALUATION OF AGGREGATE RESOURCES 

IN THE NORTH SAN FRANCISCO BAY 

P-C REGION 

Data Base 

In order for any appraisal of a resource to have credibility, 
the basis for that appraisal must be described. If the data base 
is weak, the resource appraisal must indicate this fact; converse- 
ly, if it is strong, this should also be noted. Terminology used to 
reflect the confidence level of the data base for this project have 
been adapted from the U.S. Geological Survey Circular 831 
(Appendix A of this report — p. 39). For this project, reserves 
represent tested material determined to be acceptable for com- 
mercial use, that exists within properties owned or leased by an 
aggregate producing company, and for which permission allow- 
ing mining and processing has been granted by the proper au- 
thorities. Resources include reserves as well as all similar 
potentially usable aggregate materials which may be mined in 
the future, but for which no permit allowing mining has been 
granted, or for which marketability has not been established. 

Factors Considered in Calculation of Resources 

The resource estimates given here are limited to those re- 
sources present in nonurbanized portions of the areas designated 
by the Office of Planning and Research (OPR) as subject to 
urbanization within the near future (1990) as modified for this 
study by available information from county or city planning 
departments (Plates 3.5-3.41a), and include the Russian River 
and Dry Creek sand and gravel production areas and other 
significant aggregate operations. 

Twenty-five areas were chosen as resource sectors during 
the course of this study. The sectors are identified on 24 sector 
maps (Plates 3.42-3.65), which are 1:48,000 scale editions of the 
U.S. Geological Survey quadrangles in which the sectors are 
located. The sectors are identified by the letters A through Y on 
the sector maps, in Tables 3.5 and 3.6, and in the sector descrip- 
tions below. Reserves and resources within the sectors are shown 
in Table 3.6. 

Parameters used in determining locations and volumes of 
resources within the 25 sectors included the following items: 

1 . The most detailed geologic and topographic maps avail- 
able were used for classification. Published and unpub- 
lished reports were used to locate and identify active 
and inactive quarries within the P-C region. 

2. An operating quarry was considered sufficient evidence 
that commercial-quality aggregate was present in the 
deposit. 

3. All areas classified MRZ-2 and MRZ-3 were field- 
checked, and found to contain material similar to that 
occuring in active quarries. Material suitable only for 
fill was not classified MRZ-2. 

4. The lateral and vertical distribution of the resource was 
determined on the basis of geologic projections from 
sample sites at quarries and outcrops, and on the basis 
of an understanding of the geological processes respon- 
sible for the formation of the deposit. The resource eval- 
uation of the sand and gravel deposits are based in part 
on analyses of several thousand water- well logs. The logs 



describe the types of earth materials (clay, silt, sand, 
gravel) and bedrock encountered at various depths, as 
interpreted by the well driller (who may have had little 
or no training in earth sciences). The quality of the de- 
scriptions range from bad to very good. Many water-well 
logs were unsuitable because of the incomplete descrip- 
tions of the earth materials encountered in the well. In 
some instances the location of the well was vague. Only 
well logs that contain acceptable descriptions and loca- 
tions were used in this study. 

5. Resource estimates for those deposits chosen as sectors 
are based on measurements of volumes made from base 
maps enlarged to scales of 1 :6,000 or 1 : 1 2,000. Tonnage 
conversion factors are based on density tests of samples 
from the sectors or from quarries with material similar 
to the sector material. Reserve figures for areas outside 
OPR boundaries were based on published data 
(Sonoma County Planning Department). 

Included within the boundaries of many sectors are active 
commercial aggregate operations. Reserve and resource calcula- 
tions were done in 1977 for most significant quarries or sand pits 
in the four counties, as part of a study of the aggregate industry 
in the San Francisco-Monterey Bay Region (Chesterman and 
Manson, 1983). These calculations were revised to 1980, the 
year of the most recent available production statistics to accomo- 
date resource depletion and other factors. County totals of com- 
mercial reserves and resources in the 3 P-C regions are included 
in Tables 3.6, 3.13, and 3.14 for comparison with the resources 
available in the sectors. 

Parameters used by Chesterman and Manson (1983) in 
making their calculations, largely of demonstrated reserves (see 
Appendix A), are site specific and reflect all conditions listed in 
the mine's use permit. These parameters may include some or all 
of the following items: 

1. Setbacks of excavation areas from property lines range 
from to 105 feet. Minimum setbacks usually occur 
when the excavation area is adjacent to other produc- 
ers. Maximum setbacks are delineated along public 
roads. 

2. Pit wall slopes are usually required to have a horizon- 
tal-to-vertical ratio of less than or equal to 1:1, 1.5:1, or 
2:1. Quarry walls usually are required to be benched at 
specific vertical intervals and may have sloped connect- 
ing walls. When benching is required, the width of the 
bench, if specified, often is approximately equal to one- 
half the vertical interval. This design results in an ap- 
proximate slope of 63°. Occasionally, benches are for- 
bidden and a smooth wall with a 2:1 or 3:1 slope 
is specified in the use permit. 

3. Maximum pit depth or minimum quarry floor elevation 
is indicated in many use permits. Depths of excavation 
range from 40 to 120 feet below ground surface. 

4. Densities of the in-place material vary considerably 
between individual deposits and from one rock type to 
another. Where aggregate is composed of sediments 
derived from the Franciscan Complex (as in the Rus- 
sian River Production District) a factor of 14.50 cubic 
feet per ton (0.069 tons per cubic foot) is used in re- 
serve calculations. This factor is derived from data sup- 
plied by producers in the Livermore-Amador Valley. 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



The specific gravities of rock samples from individual 
quarries range from 2.13 to 2.70, yielding individual 
conversion factors from 0.06 to 0.08 tons per cubic foot. 

Waste factors vary from plant to plant, and considera- 
ble variation within a deposit often is shown by detailed 
sampling. Most sand and gravel plants have waste fac- 
tors that range from 5 to 15 percent of gross tonnage. 
The rock quarries usually have no waste because the 
low grade material is sold for fill or topsoil. 



Table 3.5 Resource sectors in the North San Francisco Bay 
P-C Region. 



QUADRANGLE 



CLASSI- 
FICATION 



REFER- 

SECTOR ENCE 
IN TEXT 



Asti Quadrangle MRZ-2 

Cloverdale Quadrangle MRZ-2 

Geyservllle Quadrangle MRZ-2 

Jimtown Quadrangle MRZ-2 

Geyservllle Quadrangle MRZ-2 

Guernevllle Quadrangle MRZ-2 

Healdsburg Quadrangle MRZ-2 

Glen Ellen Quadrangle MRZ-2 

Sears Point Quadrangle MRZ-2 

Sonoma Quadrangle MRZ-2 

Novato Quadrangle MRZ-2 

Petaluma River Quadrangle MRZ-2 

Petaluma River Quadrangle MRZ-2 

Cotati Quadrangle MRZ-2 

Benicia Quadrangle MRZ-2 

Cuttings Wharf Quadrangle MRZ-2 

Mount George Quadrangle MRZ-2 

Napa Quadrangle MRZ-2 

San Quentin Quadrangle MRZ-2 

Petaluma River Quadrangle MRZ-2 

Glen Ellen Quadrangle MRZ-2 

Kenwood Quadrangle MRZ-2 

Sonoma Quadrangle MRZ-2 

Inverness Quadrangle MRZ-2 

Petaluma River Quadrangle MRZ-2 

Camp Meeker Quadrangle MRZ-2 

Camp Meeker Quadrangle MRZ-2 

Camp Meeker Quadrangle MRZ-2 

Bodega Head Quadrangle MRZ-2 

Petaluma River Quadrangle MRZ-2 

Petaluma River Quadrangle MRZ-2 

Duncans Mills Quadrangle MRZ-2 

Stewarts Point Quadrangle MRZ-2 

Petaluma River Quadrangle MRZ-2 

Mark West Springs Quadrangle MRZ-2 

Sears Point Quadrangle MRZ-2 

Guernevllle Quadrangle MRZ-2 



(b) 
(b) 



11 



12 



p. 13 



P. 13 



E 


P- 


14 


F 


P- 


14 


G 


P- 


14 


H 


P- 


16 


I 


P- 


16 


J 


P- 


17 


K 


P- 


17 


L 


P- 


18 


M 


P- 


18 


N 


P- 


18 





P- 


18 


P 


P- 


19 


Q 


P- 


19 


R 


P- 


19 


S 


P- 


19 


T 


P- 


19 


U 


P- 


20 


V 


P- 


20 


w 


P- 


20 


X 


P- 


20 


Y 


P- 


20 



ESTIMATED AGGREGATE RESOURCES 

OF THE 

NORTH SAN FRANCISCO BAY 

P-C REGION 



The available aggregate resources within the urbanizing 
portions of the North San Francisco Bay P-C Region are sum- 
marized by county and by sector in Table 3.6. The table identifies 
the sectors and lists the amounts of available aggregate within 
the sectors. In addition, Table 3.6 lists the amount of sand and 
gravel or stone reserves controlled by commercial aggregate 
companies within the four counties of this P-C region. In Table 
3.6, reserves are aggregate materials that a company owns or 
controls, and for which it has a valid mining permit; resources 
are the total amount of available aggregate within the sector. 
Unless noted otherwise, all resources are of the inferred category 
as described in Appendix A of this report (p. 39). 

The estimated resources within the 6 sand and gravel sec- 
tors amount to more than 908 million tons, of which approxi- 
mately 108 million tons qualify as reserves available for mining 
at the end of 1980. The sand and gravel sectors are distributed 
as follows: Marin County has 29 million tons of Novato Con- 
glomerate; Sonoma County has more than 879 million tons of 
Quaternary alluvium. 

The estimated resources within the 19 crushed stone sectors 
amount to more than 1,449 million tons, of which approximately 
432 million tons qualify as reserves available for mining at the 
end of 1980. Stone resources within the P-C region are distribut- 
ed as follows: Marin County contains more than 39 million tons 
of Franciscan Complex sandstone and Sonoma Volcanics ande- 
site; Napa County has 641 million tons of Sonoma Volcanics 
rhyolite, andesite, basalt, and tuff; western Solano County con- 
tains 413 million tons of Franciscan Complex greenstone, sand- 
stone, and silica-carbonate rocks; Sonoma County has more than 
330 million tons of basalt and rhyolite from the Sonoma Volcan- 
ics. 

The estimated P.C.C.-grade aggregate resources (from both 
crushed stone and sand and gravel deposits) within all sectors 
amount to more than 883 million tons, of which approximately 
112 million tons qualify as reserves available for mining at the 
end of 1980 (see Table 3.7). P.C.C. aggregate for the P-C region 
is obtained from three sources: the Russian River Production 
District, and stone quarries of Syar Industries and Basalt Rock 
Company. Sand and gravel obtained from the production district 
supplies the bulk of the demand for P.C.C. aggregate in the 
North San Francisco Bay P-C Region. The deposits within the 
production district consist of stream channel and flood-plain 
material, which form aquifers in the valleys along the Russian 
River. 



Sand and Gravel Resources 

In the North San Francisco Bay P-C Region, sand and 
gravel production, and sand and gravel resource sectors are 
restricted to three counties: Marin, Napa, and Sonoma. The 
principal sand and gravel production occurs in two areas — the 
Alexander Valley and Middle Reach of the Russian River — both 
in Sonoma County and both outside of the OPR urbanizing areas 
(see Figure 3.3). Relatively minor production occurs near Point 
Reyes Station (Marin County), and near the cities of Sonoma 
and Napa. Sand is dredged from marine deposits in the San 
Francisco Bay and the Carquinez Strait. 



10 



DIVISION OF MINES AND GEOLOGY 



SR 146 



Table 3.6 Reserves and resources within sectors in the North San Francisco Bay P-C Region. The reserves (calculated through 
1980) are material that commercial aggregate companies control, and for which the companies have valid mining permits. 
Resources include the reserves and any other material within the sector. 



COUNTY 



SECTOR 



SAND AND GRAVEL 
AMOUNT 
(millions of tons) 
Reserves Resources 



CRUSHED STONE 
AMOUNT 
(millions of tons) 
Reserves Resources 



Marin D 
I 
J 
L 

M 

Marin Subtotal 



29 



29 



8+ 



Parklands V 

Parklands Subtotal 

MARIN COUNTY TOTAL 



29 



31 
31 

39+ 



Western 
Solano 



413 



SOLANO COUNTY TOTAL 



413 



Napa H 

NAPA COUNTY TOTAL 



641 



641 



Sonoma A 
B 
C 
E 
F 
K 
N 

P 

Q 

R 
S 
T 

U 

w 

X 

Y 

SONOMA COUNTY TOTAL 



449 

405 

25 



108# 



879+ 



P-C REGION TOTAL 



108# 



908+ 



180# 



432# 



TOTAL RESERVES IN NORTH SAN FRANCISCO BAY P-C REGION = 540 MILLION TONS 
TOTAL RESOURCES IN NORTH SAN FRANCISCO BAY P-C REGION =2.4 BILLION TONS 

* Proprietary data 

# Includes combined proprietary data 



* 

* 

151 
* 

* 

* 

* 

* 

* 

* 

* 
* 



330# 



1,449# 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



11 



Table 3.7 Sectors that contain proven P.C.C.-grade aggre- 
gate, their resources, and any reserves that may exist within 
their boundaries. 



SECTOR MATERIAL RESOURCES RESERVES 

(Million tons) (Million tons) 



A 


S & G 


449 


* 


B 


S & G 


405 


* 


D 


S & G 


29 


- 


G 


Stone 


? 


* 


I 


Stone 


* 


* 


U 


S & G 


* 


* 


Total 


883+ 


112+ 


* Proprie 


stary 









SECTOR A: QUATERNARY ALLUVIUM - 
ALEXANDER VALLEY 

Plate 3.36 Asti Quadrangle MRZ-2(a) 

Plate 3.37 Cloverdale Quadrangle MRZ-2(a) 

Plate 3.38 Geyserville Quadrangle MRZ-2(a) 

Plate 3.41 Jimtown Quadrangle MRZ-2(a) 



Sector Plate 3.42 * 
Sector Plate 3.43 
Sector Plate 3.44 
Sector Plate 3.45 



Resource Sector A is in Alexander Valley, Sonoma County. 
The sector extends southeast along the Russian River from about 
1 mile north of Cloverdale to 3.5 miles southeast of Jimtown — 
a total distance of more than 20 miles. A comparison of topo- 
graphic maps, water-well logs, and soil survey maps (Miller, 
1972) shows that most of the sand and gravel deposits occur 
within four soil mapping units: ( 1 ) Riverwash — this consists of 
very recent deposits of gravel, sand, and silt; (2) Alluvial land, 
sandy — this unit contains soil underlain by sand and gravel 
deposits along streams; (3) Cortina very gravelly loam; and (4) 
Cortina very gravelly sandy loam. Sand and gravel is currently 
mined from gravel bars at a number of sites in Sector A. Avail- 
able water -well logs indicate that the commercial-grade sand and 
gravel extend to depths of 50-55 feet at the south end of the 
sector near Jimtown. Well logs were not available for the north- 
ern end of the sector, so an average thickness of 40 feet was 
chosen for the sand and gravel resources in Sector A. Several 
commercial aggregate operations are active in Sector A, but due 
to the large amount of reserves controlled by one company, 
reserve data is not shown here but is included with data from 
other sectors in Table 3.6. 

Sand and gravel resources for Sector A are given in the table 
at the end of this section. They were calculated be determining 
the volume of a horizontal prism, beginning below the overburden 
(at the top of the aquifer) downward to the base of the deposit. 
This technique was used in all alluvial deposits. Factors used 
(which include both factual data and assumptions in this and all 
subsequent sector tonnage calculations) in calculating resources 
included the following items: 

1. Resource material is Quaternary sand and gravel 
beneath the following U.S.D.A. soil units: Riverwash, 



* Resource sectors have not been labeled as such on the 38 quadrangles (Plates 
3.5 through 3.41a) that accompany this report. Instead, they are individually 
identified under each heading in the text, in Table 3.S and 3.6, and on individual 
sector maps (Plates 3.42 through 3.65). For example, Sector A-l is within the area 
identified by the symbol MRZ-2(a) on Plate 3.36 and within the area designated 
'Sector A-l' on Plate 3.42. Many of the resource sectors do not occupy the entire 
area classified MRZ-2 due to some restrictions caused by urbanization. 



Alluvial land, sandy, Cortina very gravelly loam, and 
Cortina very gravelly sandy loam. 

2. All sand and gravel present is suitable for P.C.C aggre- 
gate. 

3. Waste is 10 percent of the total material. 

4. Overburden (soil) is assumed to be no more than 10 
feet thick. Sand and gravel is assumed to exist from 10 
feet to 50 feet beneath the surface of Sector A. It is 
assumed that overburden has been stripped prior to the 
calculation of resources. Resource totals, therefore, do 
not include overburden. 

5. Wall slopes above the aquifer and within the deposit 
were not considered in the calculations. 

6. Ground-water table ranges from to 30 feet beneath the 
surface. Dredging can be economic at depths of at least 
50 feet. 

7. A conversion factor of 14.50 cubic feet per ton of 
material was used in calculating resources. This factor 
is based on detailed calculations for sediments derived 
from rocks of the Franciscan Complex in the Liver- 
more-Amador Valley (Alameda County) during a pre- 
vious aggregate study (Chesterman and Manson, 1983). 

8. Base maps used in calculating resources were 4:1 en- 
largements of the Asti, Cloverdale, Geyserville, and 
Jimtown 7.5 -minute quadrangles (1959, 1960, 
1955, and 1955, respectively). No allowance was made 
for material removed by stream erosion or mining since 
it is insignificant in comparison to the total resource. 



RESOURCES - SECTOR A 



SECTOR 


AREA 
(acres) 


X 


DEPTH 
(feet) 


X 


CONVERSION 
FACTORS 


TONNAGE 
= (to nearest 
10,000 tons) 


A-l 
A-l 


306.07 


X 


40 


X 


(43, 560) (.90) 
14.50 


33,100,000 



A-2(a) 

A-2(b) 
A-2(c) 

A-2(d) 



301.54 



40 



(43 ,560) (.90) 



14.50 



554.41 X 40 

384.24 X 40 

901.11 X 40 



32,610,000 

59,960,000 
41,550,000 
97,450,000 













Total 


- 


231,570,000 


A- 3 
















A- 3(a) 


365.70 


X 


40 


X 


(43, 560) (.90) 
14.50 


- 


39,550,000 


A- 3(b) 


506.26 


X 


40 


X 




- 


54,750,000 


A-3(c) 


426.88 


X 


40 


X 


Total 


- 


46,170,000 




140,470,000 


A-4 
















A-4(a) 


139.81 


X 


40 


X 


(43, 560) (.90) 
14.50 


- 


15,120,000 


A-4(b) 


267.96 


X 


40 


X 




■ 


28,980,000 



Total 
Sector A Total 



44,100,000 
449,240,000 



12 



DIVISION OF MINES AND GEOLOGY 



SR 146 



RESOURCES SECTOR A (continued) 



TOTAL RESOURCES - SECTOR A = 

449 MILLION TONS (ALL P.C.C. GRADE) 

TOTAL RESERVES - SECTOR A = 

(PROPRIETARY DATA) 




P-C BOUNOARY 

COUNTY LINE 

COASTLINE 

Scale I 500,000 



Figure 3.3 Map of the North San Francisco Bay P-C Region showing the 
location of the Russian River and Dry Creek sand and gravel production areas 
(Sectors A and B) . 



Available well logs indicate that sand and gravel extend to a 
depth of about 35 feet beneath the four soil units mentioned 
above. Several aggregate operations are active in Sector B. Data 
on reserves cannot be disclosed here for proprietary reasons, but 
are included with data from other sectors in Table 3.6. 

Resources of sand and gravel in Sector B are given in the 
table below. Factors used in calculating resources included the 
following items: 

1. Resource material is Quaternary alluvium beneath the 
four soil units (Riverwash; Alluvial land, sandy; Cor- 
tina very gravelly loam; Cortina very gravelly sandy 
loam). The sand and gravel present is suitable for 
P.C.C. aggregate. 

2. Waste is assumed to be 10 percent of the total material. 

3. Overburden (soil) is assumed to be 10 feet thick. Sand 
and gravel is assumed to be from 10 feet to 45 feet below 
ground surface in Sectors B-3 and B-4, and from 10 feet 
to 70 feet below ground surface in Sectors B-l and B-2. 

4. Wall slopes were not considered in the calculations. 

5. Ground-water table ranges from to 30 feet beneath the 
surface. Dredging of material is economic at depths of 
at least 50 feet. 

6. A conversion factor of 14.50 cubic feet per ton of 
material was used in resource calculations, due to the 
similarity of the resource material to that in Sector A. 

7. Base maps used in resource calculations were 4:1 en- 
largements of the Geyserville, Guerneville, and the 
Healdsburg 7.5 -minute quadrangles (1955). No 
allowance is made for river erosion. Approximately 22 
million tons have been mined from terrace pits as of 
1978; this figure has been subtracted from the sector 
totals. 



RESOURCES - SECTOR B 



SECTOR B: QUATERNARY ALLUVIUM 
RUSSIAN RIVER AND DRY CREEK 



Plate 3.38 Geyserville Quadrangle MRZ-2(b) Sector Plate 3.44 

Plate 3.39 Guerneville Quadrangle MRZ-2(a),(b) Sector Plate 3.46 
Plate 3.40 Healdsburg Quadrangle MRZ-2(a),(b) Sector Plate 3.47 

Resource Sector B includes the Middle Reach of the Rus- 
sian River (Sectors B-l and B-2) and Dry Creek (Sectors B-3 
and B-4). Sectors B-l and B-2 encompass the sand and gravel 
deposits along the Middle Reach of the Russian River, from 
approximately 1000 feet south of the Wohler Road bridge to 
where the river narrows, approximately a mile east of Healds- 
burg. Available water-well logs indicate that the sand and gravel 
extend to depths of up to 80 feet beneath the following soil units: 
Riverwash; Alluvial land, sandy; Cortina very gravelly loam; 
and Cortina very gravelly sandy loam. Sectors B-3 and B-4 are 
located in the drainage of lower Dry Creek from a point about 
2000 feet west of the confluence of Dry Creek and the Russian 
River to near School House Creek, a distance of about 1 5 miles. 



SECTOR 


AREA 
(acres) 


X 


DEPTH 
(feet) 


X 


CONVERSION 
FACTORS 


TONNAGE 
(to nearest 
10,000 tons) 


B-l 

B-l 


120.18 


X 


60 


X 


(43, 560) (.90) 
14.50 


19,500,000 



B-2(a) 

B-2(b) 
B-2(c) 

B-2(d) 



B-4(b) 
B-4(c) 



463.67 X 60 

618.46 X 60 

577.88 X 60 

188.30 X 60 



(43,560)(.90) 



14.50 



165.58 
72.83 



93,340,000 

100,330,000 

106,110,000 

30,550,000 
















Total 


■ 


330,330,000 


B-3 
B-3 


212.92 


X 


35 


X 


(43,560)(.90) 
14.50 


■ 


20,150,000 



35 


X 


(43, 560) (.90) 
14.50 


- 


16,630,000 


35 


X 




- 


15,670,000 


35 


X 




- 


6,890,000 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



13 



RESOURCES - SECTOR B (continued) 



OONTOUR 


AREA 




AVERAGE 




CONVERSION 




TONNAGE 


ELEVATION 


(acres) 


X 


AREA 


X 


FACTORS 


- 


(to 


nearest 








(acres) 








10,000 tons) 


B-4(d) 


97.74 


X 


35 


X 


(43,560)(.90) 
14.50 


- 


9 


,250 


000 


B-4(e) 


90.79 


X 


35 


X 


Total 


- 


8 


590 


000 




57 


030 


000 










Sector 8 Total 


- 


427 


010 


000 






Minus 


product! 


an from 
Re ma 


terrace pits 
inlng Resources 


- 


22 


000 


000 




405 


010 


000 



TOTAL RESOURCES - SECTOR B = 

405 MILLION TONS (ALL P.C.C. GRADE) 

TOTAL RESERVES - SECTOR B = 

(PROPRIETARY DATA) 



SECTOR C: QUATERNARY ALLUVIUM - 
SONOMA CREEK 

Plate 3.27 Glen Ellen Quadrangle MRZ-2(a) Sector Plate 3.48 
Plate 3.31 Sears Point Quadrangle MRZ-2(a) Sector Plate 3.49 
Plate 3.33 Sonoma Quadrangle MRZ-2(a) Sector Plate 3.50 

Resource Sector C extends southward from the Glen Ellen 
Quadrangle into the Sonoma and Sears Point quadrangles. The 
sector boundaries are approximately those of "Riverwash" as 
drawn by Miller (1972, sheets 91, 99, 100, 108). According to 
Goldman (1974, p. 49), the deposit reaches a maximum depth 
of 60 feet. Honke and Ver Planck (1950, p. 110) state that the 
material within the deposit consists predominently of andesite 
and basalt, with minor olivine basalt, vesicular lava, chert, and 
rhyolite. No test data is available concerning the suitability of 
this material for P.C.C. aggregate. 

Resources in Sector C are given in the table below. Factors 
used in calculating resources included the following items: 

1. The aggregate material is Quaternary alluvium in So- 
noma Creek within the boundaries drawn by Miller 
(1972) for "Riverwash." 

2. The sand and gravel is suitable for asphaltic concrete 
aggregate and perhaps P.C.C. aggregate. 

3. Waste (silt and clay) is assumed to form 10 percent of 
the material. 

4. Overburden is assumed to be negligible. 

5. Wall slopes are not considered in resource calculations. 

6. Average thickness of material is assumed to be 20 feet. 

7. Ground water will not hinder mining operations during 
the summer low-water period. 

8. A conversion factor of 14.50 cubic feet of material per 
ton was used. 



9. Base maps for resource calculations are 4:1 enlarge- 
ments of the Glen Ellen, Sears Point, and Sonoma 
7.5 -minute quadrangles (1980, 1968, and 1980, 
respectively). 

RESOURCES - SECTOR C 





AREA 




DEPTH 




CONVERSION 


TONNAGE 


SECTOR 


(acres) 


X 


(feet) 


X 


FACTORS 


= (to nearest 
10,000 tons) 


C-l 
C-l 


34.49 


X 


20 


X 


(43,560)(.9O) 
14.50 


1,870,000 



C-2(a) 
C-2(b) 



48.09 
69.85 



(43,560)(.9O) 



14.50 



2,600,000 
3,780,000 













Total 


" 


6,380,000 


C-3 
C-3 


28.35 


X 


20 


X 


(43, 560) (.90) 
14.50 


- 


1,530,000 


C-4 

C-4 


136.88 


X 


20 


X 


(43,560)(.90) 
14.50 


- 


7,400,000 


C-5 

C-5 


36.10 


X 


20 


X 


(43,560)(.90) 
14.50 


= 


1,950,000 



106.81 X 20 X (43,560)(.9Q ) . 5,780,000 

14.50 



Sector C Total = 24,910,000 



TOTAL RESOURCES - SECTOR C = 
25 MILLION TONS (ALL ASPHALTIC AGGREGATE GRADE) 
TOTAL RESERVES - SECTOR C = 
(PROPRIETARY DATA) 



SECTOR D: NOVATO CONGLOMERATE - 
BLACK POINT 

Plate 3.8 Novato Quadrangle MRZ-2(a) Sector Plate 3.51 

Plate 3.10 Petaluma River Quadrangle MRZ-2(c) Sector Plate 3.52 

Sector D is near Black Point (Marin County) and consists 
of two portions of a prominent ridge that is underlain by Novato 
Conglomerate, a thick accumulation of well-rounded pebbles, 
cobbles, and boulders in a well-cemented sandy matrix. Most of 
the coarse material is rhyolite or black chert. Sand and gravel 
suitable for P.C.C. aggregate formerly was produced at a quarry 
at the southern end of th. ridge. The high degree of weathering 
; n the deposit required the thorough washing of the aggregate 
(Ver Planck, 1955, p. 239). Field reconnaisance of the ridge 
indicates that the appearance of the material is uniform through- 
out the deposit, and that the deposit is urbanized except for two 
areas, one at each end. The northern area is Sector D-l, and the 
southern area is Sector D-2. 

Resource calculations for Sector D are given in the table. 
Factors used in calculating resources included the following 
items: 



14 



DIVISION OF MINES AND GEOLOGY 



SR 146 



1 . The resource material is sand and gravel of the Novato 
Conglomerate. 

2. The aggregate, when washed, is suitable for P.C.C. ag- 
gregate. 

3. Waste is estimated to be at least 20 percent. 

4. Thickness of overburden is not considered, since weath- 
ering appears to be uniform throughout the material, 
and topsoil can be sold for soil or fill material. 

5. Wall slopes would have a ratio of 2:1 (horizontal to 
vertical), and the quarry would have a minimum eleva- 
tion of 40 feet. 

6. Ground water is not expected to pose a problem to 
quarry operations. 

7. A conversion factor of 14.50 cubic feet of material per 
ton was used in calculating resources. This factor is 
derived from data supplied by producers in the Liver- 
more- Amador Valley (Alameda County), and is used 
for sediments derived from the Franciscan Complex. 
The basalt and chert in the Novato Conglomerate has 
a density of at least 2.65 when fresh; this density is 
equivalent to a factor of 12.1 cubic feet per ton, with no 
allowance for weathered material or pore space within 
the conglomerate. The only way to obtain an accurate 
figure is to perform density tests on samples of the 
conglomerate. 



Crushed Stone Resources 

In the North San Francisco Bay P-C Region, crushed stone 
production and resources are found in all four counties. As 
shown in the following sector descriptions, there are more stone 
resources available in this P-C Region than sand and gravel 
resources. There are no large production districts for crushed 
stone, but there are instead numerous small groups and scattered 
isolated producers. 



SECTOR E: SONOMA VOLCANICS BASALT - 
PETALUMA HILL 

Plate 3.10 Petaluma River Quadrangle MRZ-2(a) Sector Plate 3.52 

This basalt deposit has been quarried for paving blocks or 
crushed stone for over a century. The quarry is currently oper- 
ated by Quarry Products, Inc., and supplies asphaltic concrete 
aggregate and roadbase material. Because the entire deposit is 
controlled by a single operator, proprietary data on reserves 
cannot be released, but are included with data from other pro- 
ducers in Table 3.6. 

TOTAL RESOURCES - SECTOR E = 

(PROPRIETARY DATA, MIXED NON-P.C.C. GRADE) 

TOTAL RESERVES - SECTOR E = 

(PROPRIETARY DATA) 



Base maps for resource calculations are 4:1 enlarge- 
ments of the Novato and the Petaluma River 7.5-minute 
quadrangles (1980). No allowance is made for 
material mined since the maps were released. 

RESOURCES - SECTOR D 



CONTOUR AREA 

ELEVATION (acres) 



AVERAGE 

AREA 
(acres) 



CONVERSION 
FACTORS 



SECTOR D-l 




200 


12.57 


160 


41.32 


120 


76.96 


80 


135.04 


SECTOR D-2 




160 


4.65 


120 


28.01 


80 


35.70 


40 


89.24 



(40)(43,560)(.80) 



26.95 X 

59.14 X 

106.00 X 



16.33 
31.86 
62.47 



(40)(43,560)(.80) 



TOTAL RESOURCES - SECTOR D = 

29 MILLION TONS (ALL P.C.C. GRADE) 

TOTAL RESERVES - SECTOR D = 

TONS 



TONNACE 
(to nearest 
10,000 tons) 



2,590,000 

5,690,000 

10,190,000 

18,470,000 



1,570,000 
3,060,000 
6,010,000 

10,640,000 



SECTOR F: SONOMA VOLCANICS BASALT AND 
PETALUMA FORMATION SAND - 
STONY POINT 

Plate 3.25 Cotati Quadrangle MRZ-2(a) Sector Plate 3.53 

Basalt and weathered volcanic material of the Sonoma Vol- 
canics group are quarried for subbase, drain rock, and fill materi- 
al at the Stony Point Quarry in Sonoma County. In addition, 
overburden (which consists of sand and pebbly gravel of the 
Petaluma Formation) is stripped off and sold for fill. 

Resources in Sector F are proprietary and are included in 
with data from other producers in Table 3.6. 



TOTAL RESOURCES - SECTOR F = 

(PROPRIETARY DATA, MIXED NON-ASPHALTIC GRADE) 

TOTAL RESERVES - SECTOR F = 

(PROPRIETARY DATA) 



SECTOR G: FRANCISCAN COMPLEX - 
SULPHUR SPRINGS MOUNTAIN 

Plate 3.20 Benicia Quadrangle MRZ-2(a) Sector Plate 3.54 

Sector G lies at the southern end of Sulphur Springs Moun- 
tain (Solano County), just south of Blue Rock Springs Park, and 
is divided into 3 subsectors (Sectors G-l, G-2, and G-3). The 
Lake Herman Quarry of Syar Industries covers most of the 
northern end of the sector, and the W.E. Martin Quarry (Solano 
Excavators) is at the southwestern edge of the sector. The rocks 
underlying Sector G consist principally of metamorphosed gray- 
wacke and greenstone of the Franciscan Complex, with some 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



15 



shale and chert. Several localities within Sector G contain iron- 
stained silicified metavolcanic dike rocks that have been brec- 
ciated and hydrothermally altered. Mercury mineralization 
(cinnabar and metacinnabar) occurs along fault planes and in 
fractures in the brecciated rocks. Since only two companies have 
quarries in Sector G, reserve data is not disclosed here but is 
included with data from other sectors in Table 3.6. 

Resources within Sector G are given in the table below. 
Factors used in calculating resources included the following 
items: 

1. Resource material is Franciscan Complex graywacke, 
greenstone, chert, shale, and silicified dike rocks. 

2. Some of the rock, especially the graywacke and green- 
stone, is suitable for asphaltic concrete aggregate, and 
P.C.C. aggregate. 



RESOURCES - SECTOR G (continued) 



OONTOUR 
ELEVATION 



520 
480 
440 
400 
360 
320 
280 



AREA 
(acres) 



AVERAGE 
AREA 
(acres) 



18.37 
26.23 
33.63 
38.51 
47.98 
51.94 
67.38 



22.30 
29.93 
36.07 
43.25 
49.96 
59.66 



CONVERSION 




TONNAGE 


FACTORS 




(to nearest 
10,000 tons) 


(40)(43,560) 
11.90 


= 


3,270,000 




■ 


4,380,000 




■ 


5,280,000 




■ 


6,330,000 




- 


7,320,000 




■ 


8,740,000 


Total 


50,860,000 



3. No allowance is made for overburden or waste, since 
low-quality material is believed to form a small amount 
of the total resource. 

4. Minimum quarry elevation would be 280 feet, with a 
bench in Sector G-3 at elevation 400. 

5. Wall slopes would have a 2:1 ratio (horizontal to verti- 
cal). 

6. Ground water could pose a problem for quarry opera- 
tions with regard to both quantity and quality (i.e., 
"Sulphur Springs Mountain"). Drainage occurs at a 
mercury mine adit on the east side of the Syar Indus- 
tries property. 



SECTOR G-2 




720 


.92 


680 


2.47 


640 


3.96 


600 


5.39 


560 


8.21 


520 


12.57 


480 


16.24 


440 


19.63 


400 


25.94 



(40)(43,560) 



1.70 

3.22 

4.68 

6.80 

10.39 

14.41 

17.94 

22.79 



250,000 
470,000 
680,000 
1,000,000 
1,520,000 
2,110,000 
2,630,000 
3,340,000 

12,000,000 



7. A conversion factor of 11.90 cubic feet of material per 
ton was used in calculating tonnages. This factor is based 
on density tests performed on samples from the Syar 
Industries Quarry. 

8. The base map used in resource calculations was a 4:1 
enlargement of the Benicia 7.5-Minute Quadrangle 
(1968). No allowance is made for material mined since 
the maps were released, since it is believed to be an 
insignificant amount compared to the total resources 
available in Sector G. 

RESOURCES - SECTOR G 



CONTOUR 
ELEVATION 



AREA 
(acres) 



AVERAGE 
AREA 
(acres) 



CONVERSION 
FACTORS 



SECTOR C-l 




920 


2.12 


880 


4.53 


840 


7.98 


800 


11.77 


760 


11.82 


720 


11.88 


680 


11.82 


640 


11.71 


600 


11.77 


560 


12.45 


520 


18.37 



TONNAGE 
(to nearest 
10,000 tons) 



3.33 


X 


(40) (43, 560) 
11.90 


490,000 


6.26 


X 


- 


920,000 


9.88 


X 


. 


1,450,000 


11.80 


X 


- 


1,730,000 


11.85 


X 


- 


1,740,000 


11.85 


X 


- 


1,740,000 


11.77 


X 


" 


1,720,000 


11.74 


X 


" 


1,720,000 


12.11 


X 


. 


1,770,000 


15.41 


X 


- 


2,260,000 



920 


1.38 


880 


6.77 


840 


21.64 


800 


32.94 


760 


53.49 


720 


77.36 


680 


99.35 


640 


122.13 


600 


145.37 


560 


177.05 


520 


205.46 


480 


235.42 


440 


265.38 


400 


299.24 


Bench 




400 


274.10 


360 


272.96 


320 


263.72 


280 


250.63 



4.08 


X 


(40)(43,560) 
11.90 


- 


600,000 


14.21 


X 






- 


2,080,000 


27.29 


X 






- 


4,000,000 


43.22 


X 


- 




- 


6,330,000 


65.43 


X 


" 




- 


9,580,000 


88.36 


X 






- 


12,940,000 


110.74 


X 






- 


16,210,000 


133.75 


X 


- 




- 


19,580,000 


161.21 


X 


- 




- 


23,600,000 


191.26 


X 


- 




■ 


28,000,000 


220.44 


X 






- 


32,280,000 


250.40 


X 






■ 


36,660,000 


282.31 


X 


- 




- 


41,340,000 


273.53 


X 


. 




. 


40,050,000 


268.34 


X 






- 


39,290,000 


257.18 


X 




Total 


■ 


37,660,000 




350,200,000 



TOTAL RESOURCES - SECTOR G = 
413 MILLION TONS (MIXED AGGREGATE GRADES) 
TOTAL RESERVES - SECTOR G = 
(PROPRIETARY DATA) 



16 



DIVISION OF MINES AND GEOLOGY 



SR 146 



SECTOR H: SONOMA VOLCANICS - 
NAPA STATE HOSPITAL 

Plate 3.17 Cuttings Wharf Quadrangle MRZ-2(a) Sector Plate 3.55 
Plate 3.18 Mount George Quadrangle MRZ-2 (a) Sector Plate 3.56 
Plate 3.19 Napa Quadrangle MRZ-2 (a) Sector Plate 3.57 

Sector H encompasses a large deposit of Sonoma Volcanics 
rhyolite, andesite, basalt, perlitic rhyolite, and tuff situated at the 
common corner of the three quadrangles listed above. A portion 
of the deposit within the Napa and Mount George quadrangles, 
on the grounds of the Napa State Hospital, has been quarried 
since the turn of the century. Basalt Rock Company has oper- 
ated a quarry here for several decades. Much of the aggregate is 
suitable for asphaltic concrete, while other material can be used 
for roadbase aggregate. Since only one company has a quarry 
in Sector H, reserve data is proprietary and cannot be shown 
here, but is included with data from other companies in Table 
3.6. 

Resource calculations for Sector H are given in the table 
below. Factors used in calculating resources included the follow- 
ing items: 

1 . Crushed stone resources consist of rhyolite, andesite, 
basalt, perlitic rhyolite, and tuff of the Sonoma Volcan- 



2. The basalt is suitable for asphaltic concrete aggregate, 
while other material can be used for roadbase or sub- 
base aggregate or fill. 

3. No allowance was made for overburden or waste, since 
the percentage of low-quality material is not known. 

4. Wall slopes would have a ratio of 2:1 (horizontal to 
vertical). 

5. Minimum quarry elevation would be 100 feet. 

6. Ground water is not expected to pose a problem to 
mining. 

7. A conversion factor of 1 1.56 cubic feet of material per 
ton was used. This factor is based on density tests of 
samples from Sector H. The exact proportions of rhyo- 
lite, basalt, andesite, and tuff are unknown, so an exact 
conversion factor cannot be determined. 

8. Base maps used in calculating resources are 4: 1 enlarge- 
ments of the Cuttings Wharf, Mount George, and 
Napa 7.5-minute quadrangles (editions of 1981, 1968, 
and 1973, respectively). An allowance of 60 million 
tons is made for material mined since the maps were 
released. 



RESOURCES - SECTOR H (continued) 



CONTOUR 
ELEVATION 



AREA 
(acres) 



AVERAGE 
AREA 
(acres) 



CONVERSION 
FACTORS 



720 


1.95 


700 


5.45 


680 


9.24 


660 


13.72 


640 


19.11 


620 


22.90 


600 


29.33 


580 


37.59 


560 


47.64 


540 


62.10 


520 


77.88 


500 


95.33 


480 


115.36 


460 


138.66 


440 


164.94 


420 


196.91 


400 


227.22 


380 


268.31 


360 


315.66 


340 


362.14 


320 


417.70 


300 


463.84 


280 


500.63 


260 


535.07 


240 


568.12 


220 


603.48 


200 


639.81 


180 


676.08 


160 


714.93 


140 


755.22 


120 


795.68 


100 


829.09 



TONNAGE 
(to nearest 
10,000 tons) 



3.70 


X 


(20)(43,560) 
11.56 


- 


280,000 


7.35 


X 


" 


- 


550,000 


11.48 


X 


- 


- 


870,000 


16.42 


X 




- 


1,240,000 


21.01 


X 


- 


= 


1,580,000 


26.12 


X 


- 


- 


1,970,000 


33.46 


X 




- 


2,520,000 


42.62 


X 


" 


- 


3,210,000 


54.87 


X 




- 


4,140,000 


69.99 


X 


" 


- 


5,270,000 


86.61 


X 




- 


6,530,000 


105.35 


X 




- 


7,940,000 


127.01 


X 




- 


9,570,000 


151.80 


X 


" 


- 


11,440,000 


180.93 


X 




- 


13,640,000 


212.07 


X 


- 


- 


15,980,000 


247.77 


X 




- 


18,670,000 


291.99 


X 


•■ 


- 


22,000,000 


338.90 


X 


" 


- 


25,540,000 


389.92 


X 


- 


- 


29,390,000 


440.77 


X 


- 


- 


33,220,000 


482.24 


X 


" 


- 


36,340,000 


517.86 


X 


" 


- 


39,030,000 


551.60 


X 


- 


- 


41,570,000 


585.80 


X 


- 


- 


44,150,000 


621.65 


X 


• 


- 


46,850,000 


657.95 


X 


- 


- 


49,580,000 


695.51 


X 




- 


52,420,000 


735.08 


X 


•• 


- 


55,400,000 


775.45 


X 


- 


- 


58,440,000 


812.39 


X 


Total 


" 


61,220,000 




700,750,000 


Material 


Already 


Mined (estimate) 


-60,000,000 




Remaining Resources 


640,750,000 



TOTAL RESOURCES - SECTOR H = 
641 MILLION TONS (MIXED NON- P.C.C. GRADES) 
TOTAL RESERVES - SECTOR H = 
(PROPRIETARY DATA) 



RESOURCES - SECTOR H 



CONTOUR 


AREA 


AVERAGE 




CONVERSION 




TONNAGE 


ELEVATION 


(acres) 


X AREA 
(acres) 


X 


FACTORS 




(to nearest 
10,000 tons) 


780 


.34 






(20)(43,560) 






760 


.46 


.40 


X 


11.56 


■ 


30,000 






.78 


X 


- 


• 


60,000 


740 


1.09 
















1.52 


X 




m 


110,000 


720 


1.95 













SECTOR I: FRANCISCAN COMPLEX SANDSTONE - 
SAN PEDRO HILL 

Plate 3.14 San Quentin Quadrangle MRZ-2(a) Sector Plate 3.58 

Crushed stone suitable for P.C.C. aggregate and riprap has 
been quarried from San Pedro Hill (Marin County) since the 
turn of the century. Basalt Rock Company currently operates a 
quarry at this site. Resource material is a hard, slightly metamor- 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



17 



phosed sandstone of the Franciscan Complex, with interbedded 
black shale. The northern boundary of the MRZ-2 zone is drawn 
where detailed mapping by Rice and others ( 1976, Plate 1C) shows 
that shale becomes the predominant rock type. The shale deposits 
have been developed by several quarries, which supply material 
for bricks, tile, and lightweight aggregate. 

Resource data for Sector I is proprietary. It is included with 
data for other companies in Table 3.6. 



TOTAL RESOURCES - SECTOR I = 

(PROPRIETARY DATA, MIXED AGGREGATE GRADES) 

TOTAL RESERVES - SECTOR I = 

(PROPRIETARY DATA) 



SECTOR J: SONOMA VOLCANICS ANDESITE - 
BURDELL MOUNTAIN 

Plate 3.10 Petaluma River Quadrangle MRZ-2(b) Sector Plate 3.52 

This sector is underlain by a large block of andesite, which 
occurs within landslide debris on the east end of Burdell Moun- 
tain (Marin County), and is the largest of several such blocks 
that have moved downhill from the lava-capped crest. Accord- 
ing to Ver Planck (1955, p. 242-243), seismic tests indicate 
that the block of andesite is 200 feet thick. Smaller blocks of 
andesite have been classifed MRZ-3. The andesite is suitable for 
asphaltic concrete aggregate. A processing plant was set up at 
this site in 1954 for the production of crushed stone, but is no 
longer active. 

Resources in Sector J are given in the table below. Factors 
used in calculating resources included the following items: 

1. The resource sector contains andesite of the Sonoma 
Volcanics, and is limited to the area shown as "dis- 
turbed ground" on the 1980 photo- revised edition of 
the Petaluma River Quadrangle. 

2. The andesite is suitable for asphaltic concrete aggregate 
or roadbase material. 

3. No allowance is made for overburden or waste, since 
the amount of low-grade material is not known. 

4. Wall slopes would have a ratio of 2:1 (horizontal to 
vertical). 

5. Minimum quarry elevation would be 240 feet. 

6. Ground water is not expected to pose a problem to 
mining. 

7. A conversion factor of 1 1.90 cubic feet of material per 
ton is used in calculating resources. This factor is based 
on density tests on samples from Sector J, and assumes 
that the andesite block is homogenous throughout its 
extent. 

8. Base map for resource calculations is a 4: 1 enlargement 
of the 1980 edition of the Petaluma River 7.5-Min- 
ute Quadrangle. An allowance of 7.1 million tons is 
made for material mined since the first edition of the 
map was prepared. 



RESOURCES - SECTOR J 



CONTOUR 


AREA 




AVERAGE 




CONVERSION 




TONNAGE 


ELEVATION 


(acres) 


X 


AREA 
(acres) 


X 


FACTORS 




(to nearest 
10,000 tons) 


520 
480 


8.95 
10.22 


- 


9.59 


X 


(40)(43,560) 
11.90 


- 


1,400,000 






— 


10.71 


X 


- 


- 


1,570,000 


440 


11.19 


















— 


11.42 


X 




- 


1,670,000 


400 


11.65 


















— 


14.47 


X 




• 


2,120,000 


360 


17.28 


















— 


18.26 


X 




- 


2,670,000 


320 


19.23 


















— 


19.63 


X 




- 


2,870,000 


280 


20.03 


















— 


19.11 


X 




- 


2,800,000 


240 


18.19 


























Tota 


L 


15,100,000 






Minus 


material 


already 


mined (estimate 


> 


-7,100,000 










Remaining resources 




8,000,000 



TOTAL RESOURCES - SECTOR J = 

8 MILLION TONS (MIXED NON-P.C.C. GRADES) 

TOTAL RESERVES - SECTOR J = 

TONS 



SECTOR K: SAINT HELENA RHYOLITE - 
NUNS CANYON 

Plate 3.27 Glen Ellen Quadrangle MRZ-2 (b) Sector Plate 3.48 
Plate 3.28 Kenwood Quadrangle MRZ-2 (a) Sector Plate 3.59 
Plate 3.33 Sonoma Quadrangle MRZ-2 (b) Sector Plate 3.50 

The extensive mass of riebeckite rhyolite and volcanic tuff 
is part of the Saint Helena Rhyolite member of the Sonoma 
Volcanics, and covers portions of three quadrangles. Several 
quarries within the sector have provided decorative stone, flag- 
stone, paving blocks, and roadbase material during this century. 
At present, two companies are active; the Nuns Canyon Quarry 
and Trinity Quarry, Inc., which share the same site. Waste 
material from flagstone and decorative stone operations is sold 
for roadbase aggregate. 

Resources within Sector K are given in the table below. 
Factors used in calculating resources included the following 
items: 

1. Resource material is rhyolite and tuff of the Saint He- 
lena Rhyolite member of the Sonoma Volcanics. 

2. Material within the sector is suitable for asphaltic con- 
crete aggregate, roadbase aggregate, or fill material. 

3. No allowance is made for overburden or waste, since 
the percentage of low quality material is not known. 

4. Quarry walls would have slopes of 2:1 (horizontal to 
vertical). 

5. Minimum quarry elevation would be 400 feet. 

6. Ground water is not expected to pose a problem to 
mining. 

7. A conversion factor of 14.21 cubic feet of material per 
ton was used in resource calculations. This factor is 



DIVISION OF MINES AND GEOLOGY 



SR 146 



based on density tests of samples of rhyolite from Sector 
K, and assumes uniformity of the material within the 
deposit. 

Base maps for resource calculations are 4:1 enlarge- 
ments of the Glen Ellen, Kenwood, and Sonoma 
7.5 - minute quadrangles ( 1 980) . No allowance is made 
for material mined since the maps were issued, since 
mined material is an insignificant amount of the total 
resource. 

RESOURCES - SECTOR K 



CONTOUR 
ELEVATION 



AREA 
( acres) 



AVERAGE 
AREA 
(acres) 



CONVERSION 
FACTORS 



760 


3.44 


720 


16.99 


680 


39.54 


640 


63.53 


600 


98.37 


560 


138.49 


520 


178.43 


480 


235.94 


440 


282.08 


400 


349.23 



10.22 


X 


28.27 


X 


51.54 


X 


80.95 


X 


118.43 


X 


158.46 


X 


207.19 


X 


259.01 


X 


315.66 


X 



TONNAGE 
(to nearest 
10,000 tons) 



(40)(43,560) 


- 




14 


.21 


1,250,000 






■ 


3,470,000 






- 


6,320,000 






- 


9,930,000 






- 


14,520,000 






- 


19,430,000 






- 


25,400,000 


•■ 




- 


31,760,000 




Total 




38,700,000 




150,780,000 



Reserve data for the Borello Quarry is proprietary and can- 
not be released here, but is included with that of other quarries 
in Table 3.6. 

TOTAL RESOURCES - SECTOR L = 

(PROPRIETARY DATA, ALL ROADBASE GRADE) 

TOTAL RESERVES - SECTOR L = 

(PROPRIETARY DATA) 



SECTOR M: FRANCISCAN COMPLEX SERPENTINITE - 
GHILOTTI QUARRY 

Plate 3.10 Petaluma River Quadrangle MRZ-2(f) Sector Plate 3.52 

This sector contains approximately 50 acres and is located 
at the upper end of Bowman Canyon, on the southwest slope of 
Burdell Mountain, about 3 miles from the center of Novate 
The quarry was opened in 1965, and is operated by Ghilotti 
Brothers, Inc. The resource material in the quarry is serpentinite 
of the Franciscan Complex, and is suitable for subbase material. 
The rock is highly fractured and sheared, and is dark green to 
grayish-green in color. 

Due to the proprietary nature of the reserve data, the avail- 
able amount of material cannot be released here, but is included 
along with data from other companies in Table 3.6. 



TOTAL RESOURCES - SECTOR M = 

(PROPRIETARY DATA, ALL SUBBASE GRADE) 

TOTAL RESERVES - SECTOR M = 

(PROPRIETARY DATA) 



TOTAL RESOURCES - SECTOR K = 

151 MILLION TONS (ALL ROADBASE GRADE) 

TOTAL RESERVES - SECTOR K = 

(PROPRIETARY DATA) 



Resource Sectors 
Outside of the Urbanizing Areas 

In the North San Francisco Bay P-C Region there are ten 
significant quarries that lie outside of the OPR urbanizing areas, 
in addition to the operations in the Russian River Production 
District. Since their production has been included in reserve 
projections for the P-C Region, and these quarries meet thresh- 
old value, they have been included as sectors and are described 
below. 



SECTOR N: FRANCISCAN COMPLEX - 
BLUE ROCK COMPANY QUARRY 

Plate 3.6 Camp Meeker Quadrangle MRZ-2(b) Sector Plate 3.61 

Sector N contains approximately 31 acres, and is situated 
on the south side of Highway 116, 1 mile west of Forest ville 
(Sonoma County). The quarry is on the north slope of a hill 
along the west side of Green Valley Creek, a tributary of the 
Russian River. The material is siltstone and metasiltstone of the 
Franciscan Complex. The siltstone is bluish-gray in color, platy, 
and not suitable for uses other than fill. The metasiltstone, which 
is suitable for subbase aggregate, is dark gray to light bluish- 
gray, hard, and overlies the siltstone on a gradational contact. 

Estimates of available aggregate are not presented here, 
since reserve data are proprietary but are included with that of 
other quarries in Table 3.6. 



SECTOR L: FRANCISCAN COMPLEX - 
BORELLO QUARRY 

Plate 3.7 Inverness Quadrangle MRZ-2(a) Sector Plate 3.60 

This sector, consisting of approximately 900 acres, is situ- 
ated in Millerton Gulch, about 0.9 miles northeast of Highway 
1, and 1.1 miles east of Tomales Bay. The quarry has been in 
operation since -the late 1950s, and is owned by R.A. Borello 
Tractor Rentals. The quarry area is underlain by sandstone, 
shale, greenstone, chert, and pillow lavas of the Franciscan Com- 
plex. Reserve material is the greenstone and pillow lavas, and the 
crushed material is sold for roadbase material and drain rock. 



TOTAL RESOURCES - SECTOR N = 

(PROPRIETARY DATA, ALL SUBBASE GRADE) 

TOTAL RESERVES - SECTOR N = 

(PROPRIETARY DATA) 

SECTOR O: FRANCISCAN COMPLEX - 
CANYON ROCK COMPANY QUARRY 

Plate 3.6 Camp Meeker Quadrangle MRZ-2(a) Sector Plate 3.61 

This sector contains 85 acres located on the west side of 
Green Valley Creek, 1 mile west of Forestville on the north side 
of Highway 1 16. The sector is situated on the east side of a hill 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



19 



300 feet high, and is underlain bv siltstone and metasiltstone of 
the Franciscan Complex, similar to the material in Sector N 
above. The rock is not durable enough to serve as other than 
subbase and fill material. 

Estimates of available aggregate are not presented here, 
since reserve data are proprietary but are included with that of 
other quarries in Table 3.6. 



tion of Lakeville Road and Stage Gulch Road. The quarry is 
owned and operated by Ghilotti Brothers Construction Com- 
pany, and supplies roadbase and fill. The sector is underlain by 
greenstone, schist, interbedded chert and shale, and interbedded 
sandstone and shale of the Franciscan Complex. 

Estimates of available aggregate are not presented here, 
since reserve data are proprietary, but are included with that of 
other quarries in Table 3.6. 



TOTAL RESOURCES - SECTOR O = 

(PROPRIETARY DATA, ALL SUBBASE GRADE) 

TOTAL RESERVES - SECTOR O = 

(PROPRIETARY DATA) 



TOTAL RESOURCES - SECTOR R = 

(PROPRIETARY DATA, ALL ROADBASE GRADE) 

TOTAL RESERVES - SECTOR R = 

(PROPRIETARY DATA) 



SECTOR P: FRANCISCAN COMPLEX - 
GREEN VALLEY QUARRY 

Plate 3.6 Camp Meeker Quadrangle MRZ-2(c) Sector Plate 3.61 

This sector contains about 70 acres, and is located approxi- 
mately 500 feet west of Green Valley Road (Sonoma County) 
on a private road that leads to the Mount Gilead Bible Confer- 
ence Grounds. The quarry has been in continuous operation 
since 1935. The sector is underlain by two different types of rock 
belonging to the Franciscan Complex: interbedded siltstone and 
shale, and a massive, indurated mudstone. Rock from the quarry 
is used for roadbase and fill. Data concerning aggregate reserves 
are not presented here, since reserve data are proprietary, but are 
included with that of other quarries in Table 3.6. 



SECTOR S: SONOMA VOLCANICS - 
STAGE GULCH QUARRY 

Plate 3.10 Petaluma River Quadrangle MRZ-2(e) Sector Plate 3.52 

The Stage Gulch Quarry occupies approximately 50 acres, 
and is situated off Stage Gulch Road (Highway 116), about 7 
miles southeast of Petaluma. The quarry has been operated inter- 
mittently since the early 1940s, and produces roadbase and fill. 
The sector is underlain by basalt and agglomerate of the Sonoma 
Volcanics, interbedded with tuffaceous sediments of the Peta- 
luma Formation. 

Data concerning aggregate reserves are not presented here, 
since reserve data are proprietary, but are included with that of 
other quarries in Table 3.6. 



TOTAL RESOURCES - SECTOR P = 

(PROPRIETARY DATA, ALL ROADBASE GRADE) 

TOTAL RESERVES - SECTOR P = 

(PROPRIETARY DATA) 



SECTOR Q: FRANCISCAN COMPLEX - 
HAGEMANN QUARRY 

Plate 3.24 Bodega Head Quadrangle MRZ-2(a) Sector Plate 3.62 

The Hagemann Quarry is located about 2.5 miles east of 
Bodega Bay on Highway 1 . The sector covers approximately 26 
acres. Quarry rock consists of massive, fine-grained Franciscan 
Complex sandstone, and is sold primarily for roadbase, although 
it may be suitable for asphaltic concrete aggregate. 

Reserve data is not released here, since it is proprietary, but 
is included with data from other producers in Table 3.6. 



TOTAL RESOURCES - SECTOR Q = 

(PROPRIETARY DATA, ALL ROADBASE GRADE) 

TOTAL RESERVES - SECTOR Q = 

(PROPRIETARY DATA) 



SECTOR R: FRANCISCAN COMPLEX - 
HARTMAN QUARRY 

Plate 3.10 Petaluma River Quadrangle MRZ-2(d) Sector Plate 3.52 

This sector contains about 9.5 acres located southeast of 
Petaluma on Lakeville Road (Highway 116), near the intersec- 



TOTAL RESOURCES - SECTOR S = 

(PROPRIETARY DATA, ALL ROADBASE GRADE) 

TOTAL RESERVES - SECTOR S = 

(PROPRIETARY DATA) 



SECTOR T: FRANCISCAN COMPLEX SANDSTONE AND 
HOLOCENE STREAM CHANNEL DEPOSIT - 
BOHAN AND CANELIS QUARRY 

Plate 3.26 Duncans Mills Quadrangle MRZ-2(a) Sector Plate 3.63 

This 35-acre sector is located 3 miles east of Duncans Mills, 
about one-half mile north of Highway 116 on Austin Creek 
Road. Bohan and Canelis operate two separate deposits: a stream 
channel sand and gravel deposit, and a quarry underlain by 
fractured, fine-grained sandstone of the Franciscan Complex. 
The sandstone is sold for roadbase and fill, but may be suitable 
for asphaltic concrete aggregate. The sand and gravel is suitable 
for asphaltic concrete aggregate, and may be suitable for P.C.C. 
aggregate. 

Estimates of available aggregate are not presented here, 
since reserve data are proprietary, but are included with that of 
other quarries in Table 3.6. 



TOTAL RESOURCES - SECTOR T = 

(PROPRIETARY DATA, MIXED AGGREGATE GRADES) 

TOTAL RESERVES - SECTOR T = 

(PROPRIETARY DATA) 



20 



DIVISION OF MINES AND GEOLOGY 



SR 146 



SECTOR U: HOLOCENE SAND AND GRAVEL - 
GUALALA READY-MIX COMPANY DEPOSIT 



SECTOR Y-. FRANCISCAN COMPLEX 
INMAN SHALE PIT 



Plate 3.34 Stewarts Point Quadrangle MRZ-2(a) Sector Plate 3.64 

The sector is located at the confluence of the South Fork 
and Wheatfield Fork of the Gualala River, about one-quarter 
mile off the Annapolis Road. Gravel bar skimming in the chan- 
nel began in 1971, and has continued seasonally since then. The 
sand and gravel is suitable for P.C.C. aggregate. 

Data concerning aggregate reserves are not presented here, 
since reserve data are proprietary, but are included with that of 
other companies in Table 3.6. 



Plate 3.39 Guerneville Quadrangle MRZ-2(c) Sector Plate 3.46 

The Inman Shale Quarry occupies approximately 28 acres, 
and is located on the north side of Wallace Creek Road, about 
2 miles west of Healdsburg. The quarry has been in operation 
since the early 1940s. A very fine-grained shale of the Franciscan 
Complex is quarried for roadbase aggregate. 

Data concerning aggregate reserves are not presented here, 
since reserve data are proprietary, but are included with that of 
other quarries in Table 3.6. 



TOTAL RESOURCES - SECTOR U = 
(PROPRIETARY DATA, ALL P.C.C. GRADE) 
TOTAL RESERVES - SECTOR U = 
(PROPRIETARY DATA) 



TOTAL RESOURCES - SECTOR Y = 

(PROPRIETARY DATA, ALL ROADBASE GRADE) 

TOTAL RESERVES - SECTOR Y = 

(PROPRIETARY DATA) 



SECTOR W: FRANCISCAN COMPLEX PILLOW BASALTS - 
MARK WEST SHALE PIT 

Plate 3.41a Mark West Springs Quad . MRZ-2(a) Sector Plate 3.65 

This 65-acre sector is located on the north side of Porter 
Creek Road, immediately west of the Petrified Forest. The quar- 
ry is underlain by a fine-grained, blue-green pillow basalt of the 
Franciscan Complex. The near-surface rock is weathered to a 
red-brown and is used for road subbase. The fresh rock is suita- 
ble for roadbase. 

Estimates of available reserves of aggregate are not present- 
ed here, since reserve data are proprietary, but are included with 
that of other quarries in Table 3.6. 



TOTAL RESOURCES - SECTOR W = 

(PROPRIETARY DATA, SUBBASE AND ROADBASE GRADE) 

TOTAL RESERVES - SECTOR W = 

(PROPRIETARY DATA) 



SECTOR X: SONOMA VOLCANICS ANDESITE - 
SONOMA ROCK COMPANY DEPOSIT 

Plate 3.31 Sears Point Quadrangle MRZ-2(b) Sector Plate 3.49 

The sector is located on the east side of Highway 121, about 
7 miles south of Sonoma. Quarrying of aggregate began here in 
1906 but the quarry has been a major producer only since 1973. 
Roadbase aggregate is produced by crushing the andesite of the 
Sonoma Volcanics which overlies Franciscan sandstone and 
shale. 

Data concerning aggregate reserves are not presented here, 
since reserve data are proprietary, but are included with that of 
other quarries in Table 3.6. 



TOTAL RESOURCES - SECTOR X = 

(PROPRIETARY DATA, ALL ROADBASE GRADE) 

TOTAL RESERVES - SECTOR X = 

(PROPRIETARY DATA) 



Resource Sectors Within Parks 

It is recognized that dedicated parklands have special status 
as opposed to other current uses of sectorized land, consequently 
the resources within parks have been sectorized separately be- 
low, and the quantification of those resources are presented sepa- 
rately in the tables. The quantification of resources within park 
sectors are expressed to a lower degree of accuracy rather than 
to the higher level of accuracy reflected in the previous sections. 



SECTOR V: SONOMA VOLCANICS ANDESITE - 
BURDELL MOUNTAIN OPEN SPACE PRESERVE 

Plate 3.10 Petaluma River Quadrangle MRZ-2(b) Sector Plate 3.52 

This sector is located adjacent to Sector J on Burdell Moun- 
tain and is part of the Burdell Mountain Open Space Preserve. 
The sector includes an area of about 80 acres which is underlain 
by a large block of hard, dense andesite suitable for asphaltic 
concrete aggregate. 

Resources in Sector V are presented in the table below. 
Factors used in calculating resources including the following 
items: 

1. The resource sector contains andesite of the Sonoma 
Volcanics. 

2. The andesite is suitable for asphaltic concrete aggregate 
or roadbase material. 

3. No allowance is made for overburden or waste, since 
the percentage of low-grade material is not known. 

4. Wall slopes would have a ratio of 2:1 (horizontal to 
vertical). 

5. Minimum quarry elevation would be 280 feet. 

6. Ground water is not expected to pose a problem to 
mining. 

7. A conversion factor of 1 1.90 cubic feet of material per 
ton is used in calculating resources. This factor is based 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



21 



on density tests on samples from Sector J, and assumes 
that the andesite block is uniform in composition. 

Base map for resource calculations is the 1980 edition 
of the Petaluma River 7.5- Minute Quadrangle. 



RESOURCES - SECTOR V 



CONTOUR AREA 

ELEVATION (acres) 



AVERAGE 
AREA 
(acres) 



CONVERSION 
FACTORS 



560 


3.27 


520 


15.61 


480 


29.04 


440 


32.83 


400 


35.24 


360 


37.88 


320 


40.81 


280 


38.68 



TONNACE 
(to nearest 
100,000 tons) 







(40)(43 


.560) 


. 


1,400,000 


9.44 


X 


11. 


90 






22.33 


X 






- 


3,300,000 


30.94 


X 






= 


4,500,000 


34.04 


X 


■ 




- 


5,000,000 


36.56 


X 






- 


5,400,000 


39.35 


X 


" 




- 


5,800,000 


39.75 


X 


Total 




= 


5,800,000 




31,100,000 



TOTAL RESOURCES - SECTOR V = 

31 MILLION TONS (MIXED NON-P.C.C. GRADES) 

TOTAL RESERVES - SECTOR V = 

TONS 



aggregate industry shows that some of the P.C.C. production 
will be used for non-P.C.C. applications. It is probable that this 
practice will continue, and that P.C.C. reserves could be depleted 
in a shorter time period. P.C.C. reserves, because of their high 
quality requirements, will be the most difficult to replace as 
existing permitted deposits are depleted. It is important to realize 
that new P.C.C. as well as non-P.C.C. resources will need to 
come into production to meet the 50-year aggregate demands in 
this P-C Region. 



Population Records 



Population records were compiled and correlated with ag- 
gregate consumption records for the period 1953-1980 for the 
North San Francisco Bay P-C Region (Figures 3.4 and 3.5, 
Table 3.9). Records of population and aggregate consumption 
for this period were compiled for two adjacent regions: South 
San Francisco Bay and Monterey Bay P-C regions (Figures 
3.6-3.10). Population records and projections for the three P-C 
regions were compiled from publications of the California De- 
partment of Finance (no date, 1969, 1977a, 1977b, 1980a, 1980b, 
1981, 1982a, 1982b). Population projections for the 10-year peri- 
od from 2020 to 2030 were extrapolated by DMG staff from the 
data mentioned above. Population projections for the North San 
Francisco Bay P-C Region to the year 2030 are given in Table 
3.10. Population projections for all three P-C regions to the year 
2030 are presented in Figure 3.11. 



ESTIMATED 50-YEAR CONSUMPTION 
OF AGGREGATE 

The total projected aggregate consumption through the 
year 2030 in the North San Francisco Bay P-C Region is estimat- 
ed to be 478 million tons. This figure was obtained by correlating 
production records and population data to compute a per capita 
consumption rate, then using this consumption rate and popula- 
tion projections to make the 50-year estimate. Comparison of the 
permitted reserves total and the estimated consumption shows 
that permitted reserves amount to 113 percent of the future 
consumption. Based upon the per capita use rate, all existing 
aggregate reserves will be depleted by the year 2036, unless 
additional resources are permitted for mining or are imported. 

Since Portland cement concrete (P.C.C.) is a widely used 
construction material in our society, it is necessary that suitable 
aggregate be available in sufficient quantities. According to pro- 
duction statistics for the period 1953-1977, an average of 24 
percent of the total aggregate consumed annually in the North 
San Francisco Bay P-C Region was used in Portland cement 
concrete or concrete products (Table 3.8). Of this P.C.C. aggre- 
gate, crushed stone comprises a minor amount. 

The total projected P.C.C. -grade aggregate consumption 
through the year 2030 in the North San Francisco Bay P-C 
Region is estimated to be 115 million tons. This is based on an 
average annual per-capita consumption rate for P.C.C. -grade 
aggregate of 2.1 tons per person year year (24 percent of total 
per capita consumption). As shown in Table 3.7, more than 1 12 
million tons of permitted reserves in the Region meet P.C.C. 
aggregate specifications, which amounts to 97 percent of the 
anticipated consumption. 

If all reserves suitable for use as P.C.C. aggregate are util- 
ized for that purpose, P.C.C-grade reserves will be depleted in 
45 years (2032). However, typical marketing practice in the 



Table 3.8 Percentage of total aggregate consumed used 
for Portland cement concrete aggregate in the North San 
Francisco Bay P-C Region during the period 1953-1977. 



NORTH SAN FRANCISCO BAY P-C REGION 


Year 


P.C.C. 
ACCREGATE 
CONSUMED 


Total 
AGGREGATE 
CONSUMED 


P.C.C. AGGREGATE CONSUMED 
AS A PERCENTAGE OF TOTAL 
AGGREGATE CONSUMED 


1953 
1954 
1955 


377,629 

1,255,240 

115,245 


2,438,550 
2,573,521 
2,161,536 


15.5 

48.8 

5.3 


1956 
1957 
1958 
1959 
1960 


255,513 
158,588 
364,049 
317,863 
1,014,482 


5,107,709 
4,614,768 
2,681,399 
2,978,329 
3,450,216 


5.0 

3.4 

13.6 

10.7 

29.4 


1961 
1962 
1963 
1964 
1965 


1,401,182 
1,562,694 
1,311,640 
1,127,000 
1,141,000 


4,794,380 
4,258,601 
4,283,866 
5,156,157 
5,027,278 


29.2 
36.7 
30.6 
21.9 
22.7 


1966 
1967 
1968 
1969 
1970 


1,029,000 
1,065,374 
1,085,241 
1,109,466 
1,085,488 


4,512,147 
4,508,884 
4,641,679 
4,745,516 
4,064,338 


22.8 
23.6 
23.4 
23.4 
26.7 


1971 
1972 
1973 
1974 
1975 


869,056 
1,440,427 
1,875,636 
1,632,834 
1,166,185 


4,460,936 
5,130,327 
6,842,613 
5,360,346 
4,163,455 


19.5 
28.1 
27.4 
30.5 
28.0 


1976 
1977 
1978 
1979 
1980 


1,723,882 
1,645,092 

Not 
Available 


4,640,864 
5,475,721 
6,702,047 
7,021,777 
6,198,320 


37.1 
30.0 


Average 23.7% 



22 



DIVISION OF MINES AND GEOLOGY 



SR 146 



Per Capita Consumption Rates 

The North San Francisco Bay P-C Region had an average 
per capita consumption rate of 8.8 tons per year during the 
period 1953-1980 (Table 3.9). Due to the erratic nature of the 
annual aggregate production (see Figure 3.4), a 3 -year moving 
average of the annual production was used with the annual 
population data to compute the per capita rates for the North 
San Francisco Bay P-C Region. The average per capita rate was 
combined with the population projections for the North San 
Francisco Bay P-C Region in order to estimate aggregate con- 
sumption for the period 1981-2030 (Table 3.11). Similar tech- 
niques were used to compute per capita rates for the South San 
Francisco Bay and Monterey Bay P-C regions, and these per 
capita rates are discussed below in the section "Aggregate Re- 
sources of Adjacent P-C Regions — Estimated Consumption of 
Aggregate". 

Factors Affecting Per Capita Consumption Rates 

Per capita consumption of aggregate has varied with time 
and is different in each P-C region. Several factors, such as 
changes in urban growth rates with time, relative degrees of 
urban maturity, and major construction projects (for example, 
freeways), may account for the variations and differences. An- 
other factor may be possible incompleteness or inaccuracy of the 
production records compiled by the U.S. Bureau of Mines or of 
the population data compiled by the California Department of 
Finance. In addition, very high interest rates, such as existed in 
California during the period 1980-1982, tend to lower the 
amount of new construction in an area. 

The average annual per capita consumption rate for the 
North San Francisco Bay P-C Region may decrease, at a more 



or less steady rate, as the area becomes more urbanized until a 
steady state (urban maturity*) is reached. Should unforeseen 
events occur, such as massive urban renewal, disaster recon- 
struction, or major recession, the per capita consumption rate 
could change significantly. The presence of several major active 
fault systems within the North San Francisco Bay P-C Region 
increases the chance for a damaging earthquake and the need for 
subsequent extensive reconstruction afterwards (see Davis and 
others, 1982). 



ALTERNATIVE SOURCES OF AGGREGATE 

Alternative sources of aggregate, in addition to those depos- 
its classified MRZ-2 and MRZ-3, occur in areas within the 
North San Francisco Bay P-C Region, and in adjacent P-C 
regions. Some potential resources lie outside the OPR urbanizing 
boundaries, but still within the P-C region boundaries. Included 
within the group of potential resources are the extensions of 
several deposits classified MRZ-2 or MRZ-3. In addition, sand 
and fine gravel occur in bars on the floor of San Francisco Bay, 
between the Golden Gate Bar and the confluence of the Sacra- 
mento and San Joaquin rivers. Except for the aggregate re- 
sources in adjacent P-C regions and marine sand deposits, too 
little is known about the physical and chemical qualities of most 
of the alternative sources to permit even crude resource esti- 
mates. A general discussion about the potential resources and 
their occurrences is included in this section. 



* Urban maturity is the point in the development of an area at which construction 
materials are used primarily to maintain what has already been developed rather 
than to supply further development. 



7 


















































































































6 


















































































































5 










s_ 














/ 


---i 






































/ 


\ 


L 












1 




\ 






























</) 








/ 




\ 












^AGGREGATE CONSUMPTION 
(TONS) 
























z 

_i 

2 

3 










/ 




\ 




















































/ 




\ 




















































/ 




\ 














































2 

































































































































































































































































POPULAT 

l 


ION 

1 





























1952 1954 1956 1958 I960 1962 1964 1966 1968 1970 1972 1974 

Figure 3.4 North San Francisco Bay P-C Region: population and aggregate consumption records for years 1953-80. 



1976 



1978 1980 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



23 



Additional Crushed Stone Resources 
North San Francisco Bay P-C Region 

Basalt, andesite, and rhyolite of the Sonoma Volcanics, 
gray wacke and greenstone of the Franciscan Complex, and Cre- 
taceous conglomerate appear suitable for aggregate. Several 
deposits have been quarried for aggregate, building stone, or 
paving blocks. A reconnaissance study of potential quarry sites 
in Sonoma County was undertaken in 1979 by R. Erickson and 
three assistants for the Sonoma County Planning Department. 
Numerous deposits of sandstone, greenstone, and basalt were 
identified in the resultant report (Erickson and others, 1979b). 
Some of these deposits may be quarried in the future. Detailed 
geologic mapping and sampling will be needed to identify those 
deposits that contain sufficient material for economic operations. 

The North San Francisco Bay P-C Region contains several 
northwest-trending ridges underlain by rocks of the Franciscan 
Complex and Sonoma Volcanics (Wagner and Bortugno, 1982). 
Detailed exploration would show where suitable stone deposits 
exist in the nonurbanized, and therefore unclassified portions of 
the P-C region. 

Marine Sand and Gravel Deposits of the 
San Francisco Bay Area 

Sand and some gravel have been dredged from San Fran- 
cisco Bay for many years. According to Goldman (1969, p. 22), 
sand occurs in or immediately adjacent to existing current chan- 
nels at a number of places between the confluence of the Sacra- 
mento and San Joaquin rivers and the western edge of the 
Golden Gate Bar. The largest area of sand is on the bay floor, 
between Point San Quentin and the City of San Francisco, but 
deep water precludes dredging from much of this area. The 
largest potential source of sand outside of the Golden Gate is on 
the semicircular Golden Gate Bar. The general distribution of 
sand is shown on Figure 3.12. Other sand deposits that lie 
beneath a cover of younger bay mud have been dredged as 



Table 3.9 Population, aggregate consumption, and per 
capita consumption of aggregate in the North San Francisco 
Bay P-C Region during the period 1953-1980. 







AGGREGATE 




ANNUAL 






CONSUMPTION 


CONSUMPTION 


PER CAPITA 


YEAR 


POPULATION 


(Rounded to near- 


3-YEAR AVERAGE 


CONSUMPTION 






est 1000 Tons) 


(Tons) 


(Tons) 


1953 


308,400 


2,439.000 






1954 


325,100 


2,574,000 


2,391,000 


7.4 


1955 


342,400 


2,162,000 


3,280,000 


9.6 


1956 


361,800 


5,108,000 


3,961,000 


10.9 


1957 


380,200 


4,615,000 


4,134,000 


10.9 


1958 


396,500 


2,681,000 


3,424,000 


8.6 


1959 


413,500 


2,978,000 


3,036,000 


7.3 


1960 


431,000 


3,450,000 


3,740,000 


8.7 


1961 


444,500 


4,794,000 


4,167,000 


9.4 


1962 


460,000 


4,259,000 


4,445,000 


9.7 


1963 


477,200 


4,284,000 


4,566,000 


9.6 


1964 


495,500 


5,156,000 


4,822,000 


9.7 


1965 


514,500 


5,027,000 


4,898,000 


9.5 


1966 


527,200 


4,512,000 


4,682,000 


8.9 


1967 


540,300 


4,509,000 


4,554,000 


8.4 


1968 


553,300 


4,642,000 


4,632,000 


8.4 


1969 


565,900 


4,746,000 


4,483,000 


7.9 


1970 


571,600 


4,064,000 


4,423,000 


7.7 


l97l 


588 , 300 


4,461,000 


4,551,000 


7.7 


1972 


602,800 


5,130,000 


5,477,000 


9.1 


1973 


617,300 


6,843,000 


5,777,000 


9.4 


1974 


628,100 


5,360,000 


5,455,000 


8.7 


1975 


638,600 


4,163,000 


4,721,000 


7.4 


1976 


654,700 


4,641,000 


4,760,000 


7.3 


1977 


674,900 


5,476,000 


5,606,000 


8.3 


1978 


692,700 


6,702,000 


6,399,000 


9.2 


1979 


700,400 


7,021,000 


6,640,000 


9.5 


1980 


716,700 


6.198,000 







Average ann 
consumption 



ual per capita 
1954-1979 = 



aggregate 
8.8 tons. 



sources of fill. The bulk of this sand is on the east side of San 
Francisco Bay between Point Richmond and Bay Farm Island. 
This sand lens is cut in several places by mud-filled channels and 
may extend southward beyond Bay Farm Island (Goldman, p. 
33). In general, the areas from which sand is being excavated are 
operated under lease from the State Lands Commission, and are 
the shoal areas: Point Knox Shoal, southwest of Angel Island; 
Presidio and Alcatraz shoals, west and southwest of Alcatraz; 
Southampton Shoal, southwest of Point Richmond; and San 
Bruno Shoal, east of San Bruno. In 1971 and 1972, E. E. Welday 
and J. W. Williams of the California Division of Mines and 
Geology made a geologic reconnaissance of the marine mineral 
resources of the San Francisco Bay Region. Over 400 samples 
were collected, and samples that appeared to be of economic 
importance were analyzed. Welday (1975, p. 23) estimates that 
nearly one-half billion cubic yards of sand (predominantly me- 
dium-grained but with a significant coarse-grained fraction) is 
accessible to currently operating dredges. If dredging is possible 
at depths to 100 feet, this tonnage could be increased at least 50 
percent. The most valuable deposit is the Point Knox Shoal, as 
it contains abundant coarse material. This deposit is currently 
being dredged for P.C.C. sand. An estimate of the offshore sand 
resources of the San Francisco Bay area is presented in Table 
3.12. 

AGGREGATE RESOURCES 
OF ADJACENT P-C REGIONS 

If additional aggregate is needed in the North San Francisco 
Bay P-C Region on a short-term basis, the most readily available 
material is located in the neighboring regions — South San Fran- 
cisco Bay, Monterey Bay, and Sacramento-Fairfield P-C regions. 
On a short-term basis the active quarries in these three P-C 
regions can send large amounts of aggregate into the North San 
Francisco Bay P-C Region, but the delivered price per ton would 
be greatly increased by inflated transportation costs and by any 
supply-demand conflicts (see Tables 1.2, 1.3, and 1.4 in Part I 
of this report). The long-term (50-year) resource picture is more 
uncertain. As described in greater detail below, the South San 
Francisco Bay P-C Region is projected to have a substantial 
deficit of aggregate, while the Monterey Bay P-C Region appears 
to have a surplus of material. Projected aggregate needs and 
available supplies in the Sacramento-Fairfield P-C Region are 
currently under study. 

Resource Estimates 

Resource estimates given in this report (Part III) for P-C 
regions near or adjacent to the North San Francisco Bay P-C 
Region represent data taken from Parts II and IV of this study. 
The South San Francisco Bay P-C Region has approximately 6.3 
billion tons of aggregate in its resource sectors (1.1 billion tons 
of sand and gravel, and 5.2 billion tons of stone). At the end of 
1980, commercial deposits within the P-C region contained more 
than 259 million tons of sand and gravel reserves and 293 million 
tons of crushed stone reserves, for a total of more than 522 
million tons. The Monterey Bay P-C Region has approximately 
3.1 billion tons of aggregate within its resource sectors (0.7 
billion tons of sand and gravel, and 2.4 billion tons of stone). At 
the end of 1980, commercially controlled deposits within the P-C 
region contained 195 million tons of sand and gravel reserves and 
591 million tons of stone reserves, for a total of 786 million tons. 
Tables 3.13 and 3.14 list the resource sectors, available tonnages, 
and commercial reserves for the South San Francisco Bay and 
Monterey Bay P-C regions. 



24 



DIVISION OF MINES AND GEOLOGY 



SR 146 



7 


















































































































6 


















































































































5 
























j 


r»*^ 






































j 
















2 




\ 






























z 








/ 












TOT/1 




f 


































u. 4 
o 

IS) 


L A( 


36RE6ATE CONSUMPTION 










/ 














































o 








/ 
























































// 




















EL 
































sand And grav 






2 






\ 


[ / 








































































STONE* 






















































































































































o 


- 

























































1952 1954 1956 1958 I960 1962 1964 1966 1968 1970 1972 1974 1976 1978 1980 

Figure 3.5 North San Francisco Bay P-C Region: sand and gravel, stone, and total aggregate consumption records for years 1953—80. 



35 



30 



25 



15 



10 











































































































































































































































































































































































AGC 


5REG/ 


tf"E C 
(TO 


ONSL 
NS) 


IMPT 


ON 




























































































































































































































































































































































































POP 


ULAT 


ION 
























































































1952 1954 1956 1958 I960 1962 1964 1966 1968 1970 1972 1974 1976 1978 1980 

Figure 3.6 South San Francisco Bay P-C Region: population and aggregate consumption records for years 1953-80. 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



25 



35 



30 



25 



,20 

o 

i 



J 15 



10 



















































































































































































































































































































'OTA 

GGRE 


L ^ 
GATE 


: CO 


MSUM 


PTIC 














































' A 


N 






































































































































































/ 


V 


/ 


V 


















































/ 


\ 


/ 


\ 


/ 




























^SA 


MD t 


NO ( 


5RAV 


:l 




















\ 


/ 










































































S 




















































a 


unt 





























































1952 1954 1956 1958 I960 1962 1964 1966 1968 1970 1972 1974 1976 1978 1980 

Figure 3.7 South San Francisco Bay P-C Region: sand and gravel, stone, and total aggregate consumption records for years 1953-80. 



z 
2 4 



















































































































































































































































































































































































































































































AC 


GREG 


ATE CONSUMPTION 
(TONS) 













































































































































































































































































































































POPULATION 

1 i l 





























1952 1954 1956 1958 I960 1962 1964 1966 1968 1970 1972 1974 1976 1978 1980 

Figure 3.8 Monterey Bay P-C Region: population and aggregate consumption records for years 1953-80. 



26 



DIVISION OF MINES AND GEOLOGY 



SR 146 



7 


















































































































6 


















































































































5 

V) 

z 
o 

1- 

u. 4 

O 

in 

z 
o 

_l 
d 3 

2 


















































































































































































































































TC 


)TAL 


AGGF 


EGAT 


E CO 


MSUrw 


PTIO 


N * 


















































































2 




















































































STO 


NE 


































































/SAND AND GRAVEL 






































































n 



























































1952 1954 1956 1958 I960 1962 1964 1966 1968 1970 1972 1974 

Figure 3.9 Monterey Bay P-C Region: sand and gravel, stone, and total aggregate consumption records for years 1953-80. 



1976 1978 



1980 



1952 













































NORTH SAN FRANCISCO BAY 












































P-C REGION 










































SOUTH SAN FRANCISCO BAY 


12 




P-C REGION 


















s 


\ 




















MONTEREY BAY P-C REGION 


10 
















/ 
/ 


y 


\ 


v»^ 




































z 
o 
















/ 
/ 












"■*" 


\ 




























<r 

UJ 

a. 8 














\a 


/ > 
/ 














-^ 


v 










S* 


S 

V 














or 

UJ 

0- 














— 4— 




















"V 




L / 


/^y 




\ 

\ 


—^ 




£— 








V) 

06 














1 
1 








* 


+ 

.' 








**" 


\ 


— 


A> 




*«.„„ 
















t- 






4 


** 


»••• 




f 






























*x 


**** 




,' 


* 






4 






y 




^* 






































k 

* 


** 
+ 














^ 




^ 
















































2 
















































































































































































1954 



1956 



1958 



I960 



1962 



1964 



1966 1968 



1970 



1972 



1974 



1976 



1978 



I960 



Figure 3.10 Annual per capita consumption of aggregate in the North San Francisco Bay, South San Francisco Bay, and Monterey Bay P-C regions for years 
1954-79. 






1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



27 



Table 3. 10 Population projections, Marin, Napa, Western Solano, and Sonoma counties 1980-2030. Population projected by 
DMC from data in California Department of Finance (Ibid) for years 1995 through 2030, inclusive. 

NORTH SAN FRANCISCO BAY P-C REGION POPULATION PROJECTIONS 



TO YEAR 



MARIN 



NAPA 



SONOMA 



WESTERN SOLANO* 



TOTAL 



1980 


222,900 


99,100 


301,600 


1985 


227,200 


102,100 


347,600 


1990 


232,000 


106,300 


387,700 


1995 


247,200 


119,300 


425,200 


2000 


258,500 


131,600 


460,600 


2005 


267,500 


143,500 


495,500 


2010 


275,800 


155,800 


530,900 


2015 


284,200 


168,400 


565,900 


2020 


291,500 


180,800 


598,400 


2025 


298,800 


193,200 


630,900 


2030 


306,100 


205,600 


663,400 



93,100 


716,700 


114,700 


791,600 


133,500 


859,500 


148,600 


940,300 


164,500 


1,015,200 


181,000 


1,087,500 


198,200 


1,160,700 


215,700 


1,234,200 


232,600 


1,303,300 


249,600 


1,372,500 


266,600 


1,441,700 


)tal projected 


population. 



* Western Solano County is assumed to constitute 40% of Solano County's total projected 
Source : California Department of Finance (1977b, and 1981). 



Z 
04 



O 



o 

Q. 











-C * EG 


ON _ 












SOUTH 


SAN FRi 


XNCJSC0 


J3£JJh 


























































..ii roA 


.NCISCO 


BAY P-C 


REGION 






>• •» «< 


NORTHj 


cv RAY P-C RE G 














ION 












I 


y/iONTtK 


t_T DWl r 







1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030 



Figure 3.11 Projected populations of the North San Francisco Bay, South San Francisco Bay, and Monterey Bay P-C regions to the year 2030. 



28 



DIVISION OF MINES AND GEOLOGY 



SR 146 



Table 3.1 1 Projected aggregate consump- ^ 
tion* for the North San Francisco Bay P-C ^ 
Region, 1981-2030.** 



♦Aggregate consumption (tons) = population 
( 5-year average) x 5 year per capita 
consumption 



** Projections based on data in Tables 
3.9 and 3.10 



NORTH SAN 


FRANCISCO 


BAY P-C REGION 


PROJECTED AGGREGATE CONSUMPTION 


(Rounded 


to nearest 


100,000 tons) 






AGGREGATE 


PERIOD 




CONSUMPTION* 


1981-1985 




33,200,000 


1986-1990 




36,400,000 


1991-1995 




39,700,000 


1996-2000 




43,100,000 


2001-2005 




46,300,000 


2006-2010 




49,500,000 


2011-2015 




52,800,000 


2016-2020 




55,900,000 


2021-2025 




59,000,000 


2026-2030 
50-Year Total 


62,000,000 


478,000,000 









Table 3. 12 Marine sand resources of the San Francisco Bay area. Data from Welday ( 1975, p. 24) . Numbers in parentheses 
are the equivalent tonnage at 1.5 tons per cubic yard. 



LOCATION 


VOLUME 

Million Cubic Yards 
(Million Tons) 


TOTAL 

Million Cubic Yards 
(Million Tons) 


Vicinity of Rio Vista 
to Ant loch 


15 
(22.5) 








Steamboat Slough, 
Sacramento River 


Three Mile Slough to 
Antioch 

Antioch to Benicla 


40 
(60) 






55 
(82.5) 


Antioch to Chlpps Island 


40 








Chipps Island to Ryer Island 
Ryer Island to Benicla 

Benicla to Angel Island 


(60) 
40 

(60) 
50 

(75) 






130 
(195) 


Channel of San Pablo Bay and 
San Pablo Strait 


20 
(30) 








Channel Vicinity of 
Southampton 


20 
(30) 






40 
(60) 


Angel Island to the Golden Gate 










Point Knox Shoal 


25 (max. 
(37.5) 


depth 


75 ft.) 




Presidio Shoal 


30 
(45) 






55 
(82.5) 


San Francisco Bar (Inner) 


165 (max. 
(247.5) 
(350 @ max 
(525) 


depth 
. depth 


75 ft.) 
100 ft.) 


165 
(247.5) 


Tomales Bay 


35 
(52.5) 






35 
(52.5) 


TOTAL 480 
(720) 






1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



29 



Vallejo 



© 



.Benicia 



e&r 



Martinez 



Richmond 



*® 



S>- 



Marin 
Peninsula 



Oakland 



San Francisco 




Oakland Int'l. Airport 




Grizzly Island 



Newark 



Redwood City 



13 





Sherman 
Island 



Pittsburg 



Antioch 



1. 


Alcatraz Shoal 


2. 


Bay Farm Island 


3. 


Chipps Island 


4. 


Golden Gate Bar 


5. 


Middleground Island 


6. 


Point Knox Shoal 


7. 


Point Richmond 


8. 


Presidio Shoal 


9. 


Ryer Island 


10. 


San Bruno Shoal 


11. 


San Pablo Bay 


12. 


Southampton Shoal 


13. 


Steamboat Slough 


14. 


Tomales Bay 


15. 


Three Mile Slough 



Marine sand and gravel deposits 



N 



Fremont 



5 Mi. 



5 km 



Figure 3.12 Marine sand and gravel deposits in San Francisco Bay and Sacramento River — Delta (after E. E. Welday, 1975). Known aggregate deposits 
are shown by dot pattern. 



30 



DIVISION OF MINES AND GEOLOGY 



SR 146 



Table 3. 13 Reserves and resources within sectors in the South San Francisco Bay P-C Region. The reserves (calculated through 
1980) are material that commercial aggregate companies control, and for which the companies have valid mining permit. 
Resources include the reserves and any other material within the sector. 



COUNTY 



SECTOR 



SAND AND GRAVEL 
AMOUNT 
(millions of tons) 



CRUSHED STONE 
AMOUNT 
(millions of tons) 





Reserves 


Resources 


Reserves 


Resources 


A 


242 


383 








B 




88 








C 




99 








D 








1 


,041 


E 


* 


142 








F 


* 


* 








G 


* 


* 








H 










112 


I 










299 


J 




32 








K 




63 








L 




188 








M 






* 




23 


N 






* 




* 









* 




* 


P 






* 




* 



Alameda 



Alameda Subtotal 



Parklands 

JJ 
KK 
LL 

MM 

Parklands Subtotal 



259# 



995 + 



7 
12 



19 



20+# 



1,495# 



316 
82 

398 



ALAMEDA COUNTY TOTAL 



259# 



1,014+ 



20+ 



1,893# 



Contra Costa 



Q 

R 
S 
T 
U 
V 
W 
GG 



683 
121 

94 

29 

85+ 



CONTRA COSTA CO. TOTAL 



5+ 



54# 



1,012+ 



* Proprietary data 

# Includes combined proprietary data 



(continued) 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



31 



Table 3.13 (continued) 



COUNTY 



SECTOR 



SAND AND GRAVEL 
AMOUNT 
(millions of tons) 



CRUSHED STONE 
AMOUNT 
(millions of tons) 



San Francisco & X 
San Mateo Y 

HH 

San Francisco & 
San Mateo Subtotal 



Reserves Resources 



Reserves 



Resources 



35 
35 + 



Parklands 



NN 



1,600 



Parklands Subtotal 



1,600 



SAN FRANCISCO 
AND SAN MATEO 
COUNTIES TOTAL 



1,635+ 



Northern 


I 


Santa Clara 


Z 




AA 




BB 




CC 




DD 




EE 




FF 




II 



Northern Santa 

Clara County Subtotal 



37 



37+ 



27 


125 


* 


37 


* 


* 


* 


186 


* 


97+ 


* 


* 


* 


* 



167# 



445+ 



Parklands 



00 
PP 



38 



41 



Parklands Subtotal 




38 




41 


NORTHERN SANTA 
CLARA COUNTY TOTAL 


* 


75 + 


167# 


486+ 


P-C REGION TOTAL 


259+# 


1,122# 


293# 


5,199# 



TOTAL RESERVES IN SOUTH SAN FRANCISCO BAY P-C REGION 
TOTAL RESOURCES IN SOUTH SAN FRANCISCO BAY P-C REGION 



= 552 MILLION TONS 
=6.3 BILLION TONS 



* Proprietary data 

# Includes combined proprietary data 



32 



DIVISION OF MINES AND GEOLOGY 



SR 146 



Table 3. 14 Reserves and resources within sectors in the Monterey Bay P-C Region. The reserves (calculated through 1980) 
are material that commercial aggregate companies control, and for which the companies have valid mining permits. Resources 
include the reserves and any other material within the sector. 



COUNTY 



SECTOR 



SAND AND GRAVEL 
AMOUNT 
(millions of tons) 
Reserves Resources 



CRUSHED STONE 
AMOUNT 
(millions of tons) 
Reserves Resources 



Monterey G 
H 
I 
J 
K 
N 

P 
Monterey County Subtotal 



* 


43+ 




208 




3 


* 


* 


* 


* 


* 


* 


* 


254 + 




20 




4 



31 



31 + 



Parklands S 
T 

Parklands Subtotal 



24 



MONTEREY COUNTY TOTAL 



278 + 



31 + 



San Benito E 
F 

SAN BENITO 
COUNTY TOTAL 



226 



226 



395 



395 



Santa Cruz 



A 
B 
C 
L 

M 

Santa Cruz Subtotal 



1,004 



1,004+ 



Parklands 



TOTAL RESERVES IN MONTEREY BAY P-C REGION = 786 MILLION TONS 
TOTAL RESOURCES IN MONTEREY BAY P-C REGION =3.1 BILLION TONS 

* Proprietary data 

# Includes combined proprietary data 



381 

555 



Parklands Subtotal 








936 


SANTA CRUZ 
COUNTY TOTAL 


* 


* 


* 


1,940+ 


Southern 
Santa Clara D 
U 


* 
* 


25 
21 






SANTA CLARA 
COUNTY TOTAL 


* 


46 






P-C REGION TOTAL 


195# 


715# 


591# 


2,366+ 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



33 



Estimated Consumption of Aggregate 

Estimated 50-year aggregate consumption for nearby P-C 
regions is presented in Table 3.15. At the projected level of 
consumption (6.0 tons per person annually; 1.5 billion tons over 
50 years), the South San Francisco Bay P-C Region's reserves 
will be depleted in 12 years (1999). Thus, if reliance is placed 
solely upon these deposits, a shortfall is predicted for the South 
San Francisco Bay P-C Region and the shortfall will occur long 
before a shortfall develops in the North San Francisco Bay P-C 
Region. In contrast, the Monterey Bay P-C Region is projected 
to have a surplus of aggregate available for its 50-year needs. 
Based on an average annual per capita consumption of 7.7 tons, 
approximately 374 million tons will be needed during the next 
50 years, and 786 million tons were available at the end of 1980. 
Sand and crushed stone are currently imported into the South 
San Francisco Bay P-C Region from the Monterey Bay P-C 
Region. This arrangement will undoubtedly continue under 
present economic conditions. 

Deep Sand and Gravel Deposits Within 

the Livermore Valley - Sunol Valley - Niles Cone 

Production District 

One of the most geologically promising alternative sources 
of high quality (P.C.C.-grade) sand and gravel occurs in the 
Livermore Valley - Sunol Valley - Niles Cone Production Dis- 
trict, below the current maximum permitted mining depth of 
existing gravel pits. The few deep water-well records available 
show locally continuous deposits of sand and gravel to depths of 
more than 700 feet in the Livermore Valley, more than 400 feet 
in Sunol Valley, and more than 500 feet in the Niles Cone. The 
present level of available data is adequate only to classify these 
lower aquifers as MRZ-3 without additional drilling and testing. 

Before these deep deposits could be considered as resources, 
the thickness and continuity of interbedded aquicludes would 
require study, and the quality of the lower sand and gravel would 
need to be tested. However, since all materials in the several 
aquifers were derived from the same source rocks, and all of the 
deposits in the district are of approximately the same age, it is 
likely that rock quality would be high throughout the deposits. 

Pit depths down to 100 feet below the local water table are 
feasible with today's mining technology. Utilization of these 
deep alternative resources would require care to preserve present 
ground-water quality, but would maximize recovery of valuable 
mineral resources in the P-C Region. 

Potential Aggregate Resources 
Outside of OPR Boundaries 

Several geologic units may become sources of aggregate in 
the future, but have not been classified as part of this overall 
study because they are located outside the OPR zones in the 
Monterey Bay or South San Francisco Bay P-C regions. These 
units contain stone or sand or gravel; they appear to be suitable 
for aggregate, based on written descriptions in geological reports 
and limited field examinations. 



Sand and Gravel Resources 

Several additional sources of sand and gravel occur within 
the South San Francisco Bay P-C Region. One such potential 
source in Alameda County is the geologic unit known as the 



Livermore Gravels. This formation has a stratigraphic thickness 
of 4,000 feet, covers an estimated 75 square miles of area, and 
underlies the hills on the east and west sides of Sunol Valley 
(Hall, 1958; Huey, 1948). The Livermore Gravels exposed in the 
vicinity of Vallecitos Valley contain sand, gravel, and partially 
cemented conglomerate. Near Mission San Jose, a lithologically 
similar formation, the Irvington Gravels, has been mined for 
Portland cement concrete aggregate, and is classified MRZ-2 
and MRZ-3 in Part II of this report. Detailed mapping and 
sampling of the Livermore Gravels would be needed to delineate 
areas with suitable material in commercial quantities. 

Another potential source in the South San Francisco Bay 
P-C Region (also just outside the OPR urbanizing boundaries) 
is the Santa Clara Formation. This formation has a stratigraphic 
thickness of more than 2,000 feet, and consists of conglomerate 
and interbedded sandstone, siltstone, and clay (Dibblee, 1966). 
The Santa Clara Formation extends along the lower foothills on 
both sides (east and west) of Santa Clara Valley. Little informa- 
tion is available about the quantity and quality of the sand and 
gravel in the Santa Clara Formation on the east side of the Santa 
Clara Valley, since it has not been quarried there. The Santa 
Clara Formation on the west side of Santa Clara Valley extends 
in a northwest direction from near Los Gatos to Palo Alto. Sand 
and gravel have been recovered from the conglomerate at several 
sites near Monte Vista and Stevens Creek Reservoir. The Santa 
Clara Formation in this area has been classified MRZ-2 and 
MRZ-3. However, the Santa Clara Formation extends for some 
distance beyond the OPR urbanizing boundary where it has not 
been classified. One active quarry (Stevens Creek Quarry) lies 
inside the OPR boundary. The conglomerate occurs in discon- 
tinuous lenses or beds throughout the formation and, therefore, 
detailed mapping and sampling will be required to find suitable 
material. 

The San Benito Gravels are a group of Plio-Pleistocene 
continental deposits located south of Hollister (in San Benito 
County, Monterey Bay P-C Region). Although the gravels are 
not known to have been quarried, outcrops along Paicines Creek 
contain gravel that appears suitable. The following data are tak- 
en from Griffen (1967). The unit covers an area of approximate- 
ly 150 square miles, and has a stratigraphic thickness of at least 
2,000 feet. The main body forms a northwest-trending belt 2 
to 5 miles wide. The portion of the San Benito Gravels that 
appears suitable for aggregate is the "white sands" section, 
which extends southeast from Tres Pinos to within a mile of 
Elkhorn Ranch, and is largely confined to the hills between Tres 
Pinos Creek and the San Benito River. The "white sands" sec- 
tion of the gravels covers over 20 square miles and has a max- 
imum stratigraphic thickness of at least 800 feet. Gravel forms 
20 to 25 percent of the "white sands" section, silt and clay form 
about 5 percent, and the remaining 70 to 75 percent is sand. A 
basal section at Tres Pinos contains approximately 30 feet of 
massive silt. Detailed mapping and sampling will be needed to 
locate suitable sites for quarry operations. 

Crushed Stone Resources 

The Mindego Hill Basalt, which underlies parts of Mindego 
Hill and Langley Hill in San Mateo County, is currently being 
quarried for aggregate. Expanded operations could supply 
material needed when other nearby quarries close. Cretaceous 
granodiorite forms the bulk of Montara Mountain, which over- 
looks Half Moon Bay. Although much of the exposed material 
is weathered, the western slope of the mountain may be suitable 
for quarrying, and operations there could provide substantial 
quantities of crushed stone. Large deposits of Franciscan Com- 



34 



DIVISION OF MINES AND GEOLOGY 



SR 146 



plex graywacke and greenstone occur in the mountains south of 
Los Gatos and east of San Jose, in Santa Clara County. Both 
areas are accessible by highways. 

Portions of the Niles Canyon Formation (Cretaceous) in 
the vicinity of Niles and Sunol (Alameda County) contain very 
hard sandstones. Sandstone of the Briones Formation has been 
quarried at a number of sites between San Jose and Antioch. 
However, because of the variation in hardness and silt content 
between sites, detailed field mapping and testing will be neces- 
sary to delineate areas where suitable material exists. 

The Calera Limestone, which is associated with rocks of the 
Franciscan Complex, occurs as a discontinuous zone of lime- 
stone bodies extending southeasterly from Calera Valley (Pacifi- 
ca) in San Mateo County, through western Santa Clara County 
to New Almaden. Individual masses of limestone are as much as 
a mile in length and range from 40 feet to 2,500 feet in width. 
The largest known body of limestone occurs at Permanente in 
Santa Clara County, where the Kaiser Cement Company oper- 
ates a large quarry to obtain limestone for the Permanente ce- 
ment plant. Limestone unsuitable for the manufacture of cement 
is crushed and used for Portland cement concrete aggregate. A 



large tonnage of rock suitable for aggregate is still available at 
the Permanente Quarry. Several inactive quarries are located in 
the Calera Limestone between Pacifica and New Almaden, and 
limestone suitable for aggregate may be present. According to 
Kupferman (1980, p. 112) development of the individual depos- 
its would probably be limited to aggregate quarries "... due to 
the limited extent of each mass and the dispersion of chert inter- 
beds throughout the limestone." 

An enormous body of granite forms the northern portion of 
the Gabilan Range along the Monterey-San Benito County 
boundary (Monterey Bay P-C Region). The granite covers an 
area of approximately 12 townships (approximately 400 square 
miles). The Southern Pacific Railroad traverses the Salinas Val- 
ley, which lies on the west side of the Gabilan Range. Large 
amounts of aggregate could be supplied by rail from this granite 
to nearby P-C regions. Similar material also is available in the 
Santa Lucia Range (Monterey County), but access is difficult. 
Cretaceous sandstone deposits along the east side of the Santa 
Clara Valley in the Monterey Bay P-C Region may contain 
suitable material, but have not been tested (Rogers and Wil- 
liams, 1974, Plate 1). 



Table 3. 15 Projected aggregate consumption to the year 2030 for the South San Francisco Bay, North San Franciso Bay, and 
Monterey Bay P-C regions. 





SOUTH SAN 
P-C 


FRANCISCO BAY 
REGION 


NORTH SAN 
P-C 


FRANCISCO BAY 
REGION 


MONTEREY BAY 
P-C REGION 




5-yr per capita consump- 
tion = 30.0 tons/person 


5-yr per capita consump- 
tion = 44.0 tons/person 


5-yr per capita consumption 
= 38.5 tons/person 


YEARS 


Average 
Population 
(millions) 


♦ Aggregate 
Consumption 
(million tons) 


Average 
Population 
(millions) 


♦ Aggregate 
Consumption 
(million tons) 


Average ♦ Aggregate 
Population Consumption 
(millions) (million tons) 


1981-1985 


4.38 


128.2 


.792 


33.2 


.704 26.1 


1986-1990 


4.58 


134.1 


.860 


36.4 


.760 28.2 


1991-1995 


4.76 


139.7 


.940 


39.4 


.830 30.6 


1996-2000 


4.90 


144.4 


1.015 


43.1 


.848 33.3 


2001-2005 


5.02 


148.3 


1.087 


46.3 


.967 35.9 


2006-2010 


5.14 


151.9 


1.161 


49.5 


1.039 38.6 


2011-2015 


5.26 


155.6 


1.234 


52.8 


1.110 41.4 


2016-2020 


5.38 


159.1 


1.303 


55.9 


1.177 44.1 


2021-2025 


5.50 


162.6 


1.373 


59.0 


1.243 46.6 


2026-2030 


5.61 


166.0 


1.442 


62.0 


1.310 49.2 


Total 


1,489.8 


478.0 


374.0 



♦Aggregate consumption = Population (5-year average) X 5-year per capita consumption. 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



35 



CONCLUSIONS 

Within the North San Francisco Bay P-C Region, 25 sectors 
have been identified that contain a total of 2.4 billion tons of 
aggregate resources (0.9 billion tons of sand and gravel resources 
and 1.4 billion tons of crushed stone resources). This resource 
total includes material suitable for Portland cement concrete and 
material suitable only for asphaltic concrete, road base, or sub- 
base. 

Based upon available production data and population pro- 
jections, the North San Francisco Bay P-C Region will need 478 
million tons of aggregate during the next 50 years. Of this pro- 
jected demand, 24 percent (approximately 115 million tons) 
must be suitable for Portland cement concrete. At the end of 
1980, approximately 540 million tons of aggregate reserves exist- 
ed within the P-C region, of which more than 112 million tons 
were suitable for use as P.C.C. aggregate. Total aggregate re- 
serves amount to 113 percent of the projected demand, and 
P.C.C.-grade reserves amount to more than 97 percent of the 
projected P.C.C. aggregate demand. Unless new resources are 
permitted for mining, or alternative resources are utilized, exist- 
ing reserves will be depleted in 49 years (2036) and P.C.C. grade 
material will have been utilized where lower quality aggregate 
would have been adequate. If a major earthquake were to occur 
within the P-C region and extensive reconstruction was neces- 
sary, the depletion date could arrive in less than the projected 49 
years. 

Alternatives 

The North San Francisco Bay P-C Region has four alterna- 
tives to cope with the projected deficiency of P.C.C.-grade aggre- 
gate. Other alternatives are essentially combinations of the four 
discussed here. 

1. Permit expansion of existing gravel pits and quarries if 
additional resources exist within sectors containing ac- 
tive operations. 

2. Permit mining in the previously unmined sector. 

3. Encourage exploration and where feasible, development 
of deposits within areas classified MRZ-3 or deposits 
outside of the OPR areas. 

4. Rely upon imports of aggregate from outside of the P-C 
Region. 



Permit Expansion of Existing Gravel Pits and 
Quarries 

Four of the sectors in the P-C Region contain both permit- 
ted reserves and non-permitted resources of P.C.C.-grade aggre- 
gate. Permitted reserves are often much less than the total 



resources within a sector. The amount of sand and gravel re- 
sources within the Russian River Production District, for exam- 
ple, is much greater than the calculated amount of reserves. 
Mining of these deposits would supply all of the P.C.C.-grade 
aggregate and total aggregate needed in the North San Francisco 
Bay P-C Region. Because of the large volume of resources within 
the sectors, systematic long-range planning and development for 
the P-C Region would be possible. 

Permit Mining in Previously Unmined Sectors 

Permitting mining within the previously unmined sector 
would make available 29 million tons of P.C.C.-grade aggregate. 

Encourage Exploration and Development of 
MRZ-3 Deposits 

Several deposits classified as MRZ-3 within the North San 
Francisco Bay P-C Region are good potential sources of aggre- 
gate. Other deposits lie outside of the OPR zone and were not 
classified (marine sand and gravel deposits, and northwest- 
trending ridges underlain by rocks of the Franciscan Complex 
and Sonoma Volcanics) but may contain suitable material. In 
any of these deposits, a detailed exploration and testing program 
would be necessary to determine quality and extent of the aggre- 
gate deposit. The extraction of P.C.C.-grade aggregate from 
MRZ-3 areas could provide an alternative to mining in designat- 
ed areas that are deemed by lead agencies to be more suitable for 
purposes other than mining. 

Rely Upon Imports of Aggregate from Outside 
of the P-C Region 

This approach, in the long run, would probably be the most 
expensive to the people living in the North San Francisco Bay 
P-C Region. When the reserves of P.C.C.-grade aggregate within 
this P-C Region are depleted, consumers would have to rely on 
outside imports. Supply-and-demand economics dictate that the 
price of scarce commodities will probably rise. Aggregate should 
be no exception. Transportation costs would increase as haulage 
distances increase, and these higher costs would be borne direct- 
ly or indirectly by all consumers within the P-C Region. 

Adverse environmental impacts would accompany this al- 
ternative. These include increase air emissions and fuel con- 
sumption by haul vehicles, and increased wear to local highways 
and rail lines. 

While reliance on outside imports could alleviate any short- 
term deficit in the North San Francisco Bay P-C Region, adja- 
cent P-C Regions cannot provide an unlimited supply of aggre- 
gate over the long term. Only the Monterey Bay P-C Region 
contains reserves in excess of its own 50-year needs, but this 
excess is insufficient to balance the shortfall in the South San 
Francisco Bay P-C Region. A long-term solution other than the 
import alternative is clearly needed. 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



37 



ACKNOWLEDGMENTS 



The Division of Mines and Geology gratefully acknowl- 
edges the full cooperation of local government agencies and the 
aggregate producers called upon for information during the 
course of this study. Special thanks are extended to the Associa- 
tion of Bay Area Governments, the planning departments of 
Marin, Napa, Solano, and Sonoma counties, the California De- 
partment of Water Resources, and the California Department of 
Parks and Recreation. The Pacific Gas and Electric Company 
supplied maps of its natural gas and electric power distribution 
networks. 

Frederick C. Kruger, Mining and Economic Geologist, was 
retained as a consultant to review the methods and results of the 
study. Dr. Kruger's valuable commentary and suggestions were 
instrumental in completing this report. 

Many DMG personnel assisted the authors in completing 
this report. Ralph C. Loyd, Associate Geologist, helped prepare 



50-year population projections for the three P-C regions. Russell 
V. Miller and E. Leivas, associate geologists, assisted with 
classification work. Michael A. Silva, Geologic Aid, assisted 
with water-well analysis in Sonoma County. Typing and clerical 
support was supplied by Marianne Roja, Delores Abraham, Che- 
ryl Zeh, Fe Lozaro, Marchella Porche, Marilynn Hicks, Renita 
Stone, Solita Religiose Laura Gasner, and Darren White. Draft- 
ing was done by Richard Moar, Donald Anderson, Francis Rub- 
ish, Eleanor Taylor, Janet Smith , Jeffrey Tambert, Louise 
Huckaby, Edward Foster, and Anna Stratton. Word processing 
support was provided by the Department's Word Processing 
Center under the supervision of Patty Taylor. 

Guidance throughout the course of the study was provided 
by James F. Davis, Rudolph G. Strand, Paul K. Morton, and 
David J. Beeby. 



REFERENCES 



Anderson, T.P., Loyd, R.C., Clark, W.B., Miller, R.V., Corballey, R., Kohler, S., 
and Bushnell, M.M., 1979, Mineral land classification of the Greater Los 
Angeles area, Parts I and II: Division of Mines and Geology Special 
Report 143, 79 p. 

Association of Bay Area Governments, 1974, Projections of the region's 
future; population, employment, and use alternatives in the San Fran- 
cisco Bay region: 1970-2000, Series 2, 80 p. 

Association of Bay Area Governments, 1979, Projections 79; population, 
employment, housing for the San Francisco Bay Area 1980-2000, 
79 p. 

Averill, C.V., 1929, Napa County: Twenty-fifth Report of the State Mineralo- 
gist, California State Mining Bureau, p. 213-242. 

Bailey, E.H., and Hardin, D.R., 1975, Map showing mineral resources of the 
San Francisco Bay region, California — present availability and planning 
for the future: U.S. Geological Survey Miscellaneous Investigations 
Series Map 1-909, scale 1:250,000. 

Blake, M.C., Jr., Bartow, J. A., Frizzell, V.A., Jr., Schlocker, J., Sorg, D., 
Wentworth, CM., and Wright, R.H., 1974, Preliminary geologic map of 
Marin and San Francisco counties, and parts of Alameda, Contra Costa, 
and Sonoma counties, California: U.S. Geological Survey Miscellaneous 
Field Studies Map MF-574, 2 sheets, scale 1:62,500. 

Bradley, W.W., 1915, Napa County: Fourteenth Report of the State 
Mineralogist, California State Mining Bureau, p. 262-299. 

Bradley, W.W., 1918, Quicksilver resources of California: California State 
Mining Bureau Bulletin 78, p. 171-172. 

California Department of Finance, no date, Intercensal estimates of total 
population, California counties, July 1, 1950 to July 1, 1959, 2 p. 

California Department of Finance, 1969, California Statistical Abstracts, 
Table B-6 (p. 12) and Table B-8 (p. 15). 

California Department of Finance, 1977a, California Statistical Abstracts, 
Table B-3 (p. 8) and Table B-4 (p. 9). 



California Department of Finance, 1977b, Population projections for Califor- 
nia counties 1975-2020, with age/sex detail to 2000: Population Re- 
search Unit Report, Series E-150, Report 77 P-3, 34 p. 

California Department of Finance, 1980a, Interim population projections, 
1980-1985, Baseline E-150 (Revision): Population Research Unit Re- 
port P-l, 3 p. 

California Department of Finance, 1980b, Population estimates of California 
cities and counties 1979, and January 1, 1980: Population Research 
Unit Report 80 El, 3 p. 

California Department of Finance, 1981, Interim total population projections 
1980-1990: Population Research Unit Report 81 P-l, 2 p. 

California Department of Finance, 1982a, Preliminary intercensal estimates 
of the population of California State and counties 1970—1980: Popula- 
tion Research Unit Report I 70-80, 2 p. 

California Department of Finance, 1982b, Population estimates for California 
counties — July 1, 1980 and July 1, 1981: Population Research Unit 
Report 81 E-2, 3 p. 

Chesterman, C.W., and Manson, M.W., 1983, Aggregates in the San Fran- 
cisco Bay region, California: Unpublished report, Division of Mines 
and Geology Special Report 147 (in press). 

Davis, F.F., 1948, Mines and mfneral resources of Napa County, California: 
California Journal of Mines and Geology, v. 44, no. 2, p. 159 - 188. 

Davis, J.F., Bennett, J.H., Borchardt, G.A., Kahle, J.E., Rice, S.J., and Silva, 
M.A., 1982, Earthquake planning scenario for a magnitude 8.3 earth- 
quake on the San Andreas fault in the San Francisco Bay area: 
Division of Mines and Geology Special Publication 61, 160 p., 8 
plates. 

Dibblee, T.W., Jr., 1966, Geology of the Palo Alto quadrangle, Santa Clara 
and San Mateo counties, California: Division of Mines and Geology 
Map Sheet 8, scale 1:62,500. 

Erickson, R., Demaree, R., Kautsky, M., and Thormalen, D., 1979a, Geology 



38 



DIVISION OF MINES AND GEOLOGY 



SR 146 






of existing hardrock quarries in Sonoma County: Unpublished report for 
Sonoma County Planning Department. 

Erickson, R., Demaree, R., Kautsky, M., and Thormalen, D., 1979b, Reconnais- 
sance of potential hardrock quarry sites, Sonoma County, California: 
Part II of the Sonoma County Quarry Study: Unpublished report for 
Sonoma County Planning Department. 

Ford, R.S., 1975, Evaluation of ground-water resources — Sonoma County: 
California Department of Water Resources, Bulletin 118-4, Volume 1, 
Geologic and hydrologic data, 177 p., 2 plates. 

Fox, K.F., Jr., Sims, J.D., Bartow, J.A., and Helley, E.J., 1973, Preliminary 
geologic map of eastern Sonoma County and western Napa County, 
California: U.S. Geological Survey Miscellaneous Field Studies Map 
483, 4 sheets, scale 1:62,500. 

Gealey, W.K., 1951, Geology of the Healdsburg quadrangle, California: 
California Division of Mines Bulletin 161, 50 p., 3 plates, scale 1:62,- 
500. 

Goldman, H.B., Jr., 1964, Sand and gravel in California: Division of Mines 
and Geology Bulletin 180, Part B — Central California, p. 30, 40, 42- 
43, 49. 

Goldman, H.B., Jr., 1969, Salt, sand, and shells: Mineral resources of San 
Francisco Bay, in Goldman, H.B., Jr., editor, Geologic and engineering 
aspects of San Francisco Bay fill: Division of Mines and Geology 
Special Report 97, p. 33-35. 

Griffen, W.L., 1967, Provenance, deposition, and deformation of the San 
Benito Gravels, California, in Durham, D.L., Forrest, L.C., Pierce, R.L., 
and Polugar, M., editors, Guidebook — Gabilan Range and adjacent 
San Andreas fault, American Association of Petroleum Geologists, p. 
61-73. 

Hall, C.A., Jr., 1958, Geology and paleontology of the Pleasanton area, 
Alameda and Contra Costa counties, California: University of California 
Publications in Geological Sciences, v. 34, no. 1, p. 1-90, Figure 1, Plate 
1, scale 1:48,000. 

Herbst, CM., 1979, Meeting water demands in the City of Rohnert Park: 
California Department of Water Resources, 125 p., 8 plates. 

Honke, M.T., Jr., and Ver Planck, W.E., Jr., 1950, Mines and mineral re- 
sources of Sonoma County, California: California Journal of Mines and 
Geology, v. 46, No. 1, p. 83-142. 

Huey, A.S., 1948, Geology of the Tesla quadrangle, California: Division 
of Mines Bulletin 140, p. 47-48, Plate 1, scale 1:62,500. 

Kupferman, S., 1980, Franciscan limestone geology and resources at Per- 
manente and New Almaden, Santa Clara County, California, in Loyd, 
R.C., and Rapp J.S., editors. Mineral resource potential of California: 
Sierra Nevada Section, Society of Mining Engineers, American Institute 
of Mining, Metallurgical, and Petroleum Engineers, p. 104-112. 

Miller, V.C., 1972, Soil survey of Sonoma County, California: U.S. Depart- 
ment of Agriculture, Soil Conservation Service, Plates 2, 10, 20, 21, 
29-31, 39-41, 48-50, 56-58, 64, 65, 72, scale 1:20,000. 

Rice, S.J. and Smith, T.C., 1976, Tiburon Peninsula and Sausalito geology, 
in Rice, S.J., Smith, T.C., and Strand, R.G., Geology for planning, 
central and southeastern Marin County, California: California Division 
of Mines and Geology Open-File Report 76-2 SF, Plate IE, scale 
1:12,000. 

Rice, S.J., Smith, T.C., and Strand, R.G., 1976, Geology for planning, central 
and southeastern Marin County, California: California Division of Mines 
and Geology Open-File Report 76-2 SF. 

Rogers, T.H., and Williams, J.W., 1974, Potential seismic hazards in Santa 
Clara County, California: California Division of Mines and Geology 
Special Report 107, Plate 1, scale 1:62,500. 



Schlocker J., 1974, Geology of the San Francisco north quadrangle, Califor- 
nia: U.S. Geological Survey Professional Paper 782, 109 p., 3 plates, 
scale 1:24,000. 

Sims, J.D., Fox, K.F., Jr., Bartow, J. A., and Helley, E.J., 1973, Preliminary 
geologic map of Solano County, and parts of Napa, Contra Costa, 
Marin, and Yolo counties, California: U.S. Geological Survey Miscella- 
neous Field Studies Map MF-484, 5 sheets, scale 1:62,500. 

Smith, T.C., 1976, Geology of the San Geronimo Valley area, Marin County, 
California, in Rice, S.J., Smith, T.C., and Strand, R.G., Geology for 
planning in central and southeastern Marin County, California: Divi- 
sion of Mines and Geology Open-File Report 76-2 SF, Plate 1A, scale 

1:12,000. 

Sonoma County Planning Department, 1981, Aggregate Resources Manage- 
ment Plan, p. 130. 

Travis, R.B., 1952, Geology of the Sebastopol quadrangle, California: Cali- 
fornia Division of Mines Bulletin 162, 33 p., 3 plates, scale 1:62,500. 

Ver Planck, W.E., 1955, Mines, mineral resources, and mineral industries of 
Marin County, California: California Journal of Mines and Geology, v. 
51, no. 3, p. 221-289. 

Wagner, D.L., and Bortugno, E.J., 1982, Geologic map of the Santa Rosa 
quadrangle, California: California Division of Mines and Geology, Re- 
gional Geologic Map Series, Map 2A, sheet 1, scale 1:250,000. 

Weaver, C.E., 1949, Geology and mineral deposits of an area north of San 
Francisco Bay, California: California Division of Mines Bulletin 149, 135 
p., 20 plates, scale 1:62,500. 

Welday, E.E., 1975, Marine mineral deposits in the San Francisco Bay region: 
California Division of Mines and Geology unpublished report, 27 p., 
3 plates, scale 1:125,000. 

Western Economic Research Company, no date, Basic items by census tracts 
in northern California, showing 1970 census data for census tracts for 
48 counties, 38 p. 



The following list of references includes only those cited by Rice, Smith , 
and Strand (1976) in the description of the Ring Mountain area that is 
quoted in the main body of this report (p. 5-7). The original report 
includes many more references on Ring Mountain and the Tiburon Peninsula 
in general: 



Dudley, P.P., 1967, Glaucophane schists and associated rocks of the Tiburon 
Peninsula, Marin County, California: Ph.D. thesis, University of Califor- 
nia, Berkeley, 116 p., unpublished. 

Hotz, V., and Clewlow, C.W., 1974, A northern California petroglyph site: 
The Masterkey, October-December, 1974, p. 148-152. 

Ransom, F.L., 1895, on lawsonite, a new rock-forming mineral from the 
Tiburon Peninsula, Marin County, California: University of California 
Publication, Bulletin of the Department of Geology, v. 1, no. 10, p. 
301-312. 

Rice, S.J., 1964, A trip to the lawsonite-type locality: Division of Mines 
and Geology, Mineral Information Service, v. 17, no. 6, p. 96-98. 

Rice, S.J., and Smith, T.C., 1976, Geology for Planning, central and south- 
eastern Marin County, California, Tiburon Peninsula and Sausalito geol- 
ogy: Division of Mines and Geology Open File Report 76-2 SF, 
Plate IE. 



APPENDIX A 

Principles of the Mineral Resources Classification 
System of the U.S. Bureau of Mines and the 

U.S. Geological Survey 
(From U.S. Geological Survey Circular 831) 



Principles of a 

Resource/Reserve Classification 
For Minerals 



By the U.S. Bureau of Mines and 
the U.S. Geological Survey 



GEOLOGICAL SURVEY CIRCULAR 831 



A revision of the classification system 

published as U.S. Geological Survey Bulletin 1450-A 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



43 



Principles of a Resource/Reserve Classification 

for Minerals 



By the U.S. BUREAU OF MINES and the U.S. GEOLOGICAL SURVEY 



INTRODUCTION 

Through the years, geologists, mining engineers, 
and others operating in the minerals field have 
used various terms to describe and classify mineral 
resources, which as defined herein include energy 
materials. Some of these terms have gained wide 
use and acceptance, although they are not always 
used with precisely the same meaning. 

Staff members of the U.S. Bureau of Mines and 
the U.S. Geological Survey collect information 
about the quantity and quality of all mineral 
resources, but from different perspectives and with 
different purposes. In 1976, a team of staff 
members from both agencies developed a common 
classification and nomenclature, which was 
published as U.S. Geological Survey Bulletin 
1450-A- "Principles of the Mineral Resource 
Classification System of the U.S. Bureau of Mines 
and U.S. Geological Survey." Experience with this 
resource classification system showed that some 
changes were necessary in order to make it more 
workable in practice and more useful in long-term 
planning. Therefore, representatives of the U.S. 
Geological Survey and the U.S. Bureau of Mines 
collaborated to revise Bulletin 1450-A. 

Long-term public and commercial planning must 
be based on the probability of discovering new 
deposits, on developing economic extraction proc- 
esses for currently unworkable deposits, and on 
knowing which resources are immediately 
available. Thus, resources must be continuously 
reassessed in the light of new geologic knowledge, 
of progress in science and technology, and of shifts 
in economic and political conditions. To best serve 
these planning needs, known resources should be 
classified from two standpoints: (1) purely geologic 
or physical/chemical characteristics -such as 
grade, quality, tonnage, thickness, and depth -of 



the material in place: and (2) profitability analyses 
based on costs of extracting and marketing the 
material in a given economy at a given time. The 
former constitutes important objective scientific 
information of the resource and a relatively un- 
changing foundation upon -which the latter more 
variable economic delineation can be based. 

The revised classification system, designed 
generally for all mineral materials, is shown 
graphically in figures 1 and 2 (see page 5); its com- 
ponents and their usage are described in the text. 
The classification of mineral and energy resources 
is necessarily arbitrary, because definitional 
criteria do not always coincide with natural boun- 
daries. The system can be used to report the status 
of mineral and energy-fuel resources for the Na- 
tion or for specific areas. 

RESOURCE/RESERVE DEFINITIONS 

A dictionary definition of resource, "something 
in reserve or ready if needed," has been adapted 
for mineral and energy resources to comprise all 
materials, including those only surmised to exist, 
that have present or anticipated future value. 

Resource. - A concentration of naturally occurring 
solid, liquid, or gaseous material in or on the 
Earth's crust in such form and amount that 
economic extraction of a commodity from the 
concentration is currently or potentially 
feasible. 

Original Resource. -The amount of a resource 
before production. 

Identified Resources. - Resources whose location, 
grade, quality, and quantity are known or 
estimated from specific geologic evidence. 
Identified resource* include economic, 
marginally economic, and subeconomic com- 
ponents. To reflect varying degrees of geologic 



44 



DIVISION OF MINES AND GEOLOGY 



SR 146 



(Identified Resources -Continued) 

certainty, these economic divisions can he sub- 
divided into measured, indicated, and 
inferred. * 

Demonstrated. - A term for the sum of meas- 
ured plus indicated. 

Measured. -Quantity is computed from 
dimensions revealed in outcrops, 
trenches, workings, or drill holes; 
grade and(or) quality are computed 
from the results of detailed sampling. 
The sites for inspection, sampling, and 
measurement are spaced so closely and 
the geologic character is so well de- 
fined that size, shape, depth, and 
mineral content of the resource are 
well established. 
Indicated. -Quantity and grade and(or) 
quality are computed from information 
similar to that used for measured 
resources, but the sites for inspection, 
sampling, and measurement are far- 
ther apart or are otherwise less ade- 
quately spaced. The degree of assur- 
ance, although lower than that for 
measured resources, is high enough to 
assume continuity between points of 
observation. 
Inferred. -Estimates are based on an as- 
sumed continuity beyond measured and(or) 
indicated resources, for which there is 
geologic evidence. Inferred resources may 
or may not be supported by samples or 
measurements. 
Reserve Base. -That part of an identified resource 
that meets specified minimum physical and 
chemical criteria related to current mining and 
production practices, including those for 
grade, quality, thickness, and depth. The 
reserve base is the in-place demonstrated 
(measured plus indicated) resource from which 
reserves are estimated. It may encompass 
those parts of the resources that have a 
reasonable potential for becoming economical- 
ly available within planning horizons beyond 
those that assume proven technology and cur- 
rent economics. The reserve base includes those 



'The terms "proved," "probable," and "possible", which are commonly used by in 
dustry in economic evaluations of ore or mineral fuels in specific deposits or districts, 
have been loosely interchanged with the terms measured, indicated, and inferred. 
The former terms are not a part of this classification system. 



(Reserve Base -Continued) 

resources that are currently economic 
(reserves), marginally economic (marginal 
reseroes), and some of those that are currently 
subeconomic (subeconomic resources). The 
term "geologic reserve" has been applied by 
others generally to the reserre-base category, 
but it also may include the inferred-reserve- 
base category; it is not a part of this classifica- 
tion system. 

Inferred Reserve Base. -The in-place part of an 
identified resource from which inferred 
reserves are estimated. Quantitative estimates 
are based largely on knowledge of the geologic 
character of a deposit and for which there may 
be no samples or measurements. The estimates 
are based on an assumed continuity beyond the 
reserve base, for which there is geologic 
evidence. 

Reserves. -That part of the reserve base which 
could be economically extracted or produced at 
the time of determination. The term reserves 
need not signify that extraction facilities are in 
place and operative. Reserves include only 
recoverable materials; thus, terms such as "ex- 
tractable reserves" and "recoverable reserves" 
are redundant and are not a part of this classi- 
fication system. 

Marginal Reserves. -That part of the reserve base 
which, at the time of determination, borders on 
being economically producible. Its essential 
characteristic is economic uncertainty. In- 
cluded are resources that would be producible, 
given postulated changes in economic or tech- 
nologic factors. 

Economic. -This term implies that profitable 
extraction or production under defined invest- 
ment assumptions has been established, ana- 
lytically demonstrated, or assumed with 
reasonable certainty. 

Subeconomic Resources. -The part of identified re- 
sources that does not meet the economic 
criteria of reserves and marginal reserves. 

Undiscovered Resources. - Resources, the existence 
of which are only postulated, comprising 
deposits that are separate from identified 
resources. Undiscovered resources may be 
postulated in deposits of such grade and 
physical location as to render them economic, 
marginally economic, or subeconomic. To 
reflect varying degrees of geologic certainty, 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



45 



(Undiscovered Resources - Continued) 

undiscovered resources may be divided into 
two parts: 

Hypothetical Resources. -Undiscovered re- 
sources that are similar to known mineral 
bodies and that may be reasonably ex- 
pected to exist in the same producing 
district or region under analogous geologic 
conditions. If exploration confirms their 
existence and reveals enough information 
about their quality, grade, and quantity, 
they will be reclassified as identified 
resources. 
Speculative Resources. - Undiscovered re- 
sources that may occur either in known 
types of deposits in favorable geologic set- 
tings where mineral discoveries have not 
been made, or in types of deposits as yet 
unrecognized for their economic potential. 
If exploration confirms their existence and 
reveals enough information about their 
quantity, grade, and quality, they will be 
reclassified as identified resources. 
Restricted Resources/Reserves. -That part of any 
resource/reserve category that is restricted 
from extraction by laws or regulations. For ex- 
ample, restricted reserves meet all the re- 
quirements of reserves except that they are 
restricted from extraction by laws or regula- 
tions. 

GUIDELINES FOR CLASSIFICATION OF 
MINERAL RESOURCES 

1. All naturally occurring metals, nonmetals, 
and fossil fuels in sufficient concentration can be 
classified in one or more of the categories. 

2. Where the term reserves is used alone, 
without a modifying adjective such as indicated, 
marginal, or inferred, it is to be considered 
synonymous with the demonstrated-economic 
category, as shown in figure 1. 

3. Definitions of resource categories can be 
modified for a particular commodity in order to 
conform with accepted usage involving special 
geological and engineering characteristics. Such 
modified definitions for particular commodities will 
be given in forthcoming government publications. 

4. Quantities, qualities, and grades may be ex- 
pressed in different terms and units to suit 
different purposes, but usage must be clearly 
stated and defined. 



5. The geographic area to which any 
resource/reserve estimate refers must be defined. 

6. All estimates must show a date and author. 

7. The reserve base is an encompassing 
resource category delineated by physical and 
chemical criteria. A major purpose for its recogni- 
tion and appraisal is to aid in long-range public and 
commercial planning. For most mineral com- 
modities, different grades and tonnages, or other 
appropriate resource parameters, can be specified 
for any given deposit or area, or for the Nation, 
depending on the specific objectives of the 
estimators; therefore, the position of the lower 
boundary of the reserve base, which extends into 
the subeconomic category, is variable, depending 
on those objectives. The intention is to define a 
quantity of in-place material, any part of which 
may become economic, depending on the extrac- 
tion plans and economic assumptions finally used. 
When those criteria are determined, the initial 
reserve-base estimate will be divided into three 
component parts: reserves, marginal reserves, and 
a remnant of subeconomic resources. For the pur- 
pose of Federal commodity assessment, criteria for 
the reserve base will be established for each com- 
modity. 

8. Undiscovered resources may be divided in ac- 
cordance with the definitions of hypothetical and 
speculative resources, or they may be divided in 
terms of relative probability of occurrence. 

9. Inferred reserves and the inferred reserve 
base are postulated extensions of reserves and of 
the reserve base. They are identified resources 
quantified with a relatively low degree of certainty. 
Postulated quantities of resources not based on 
reserve/reserve-base extensions, but rather on 
geologic inference alone, should be classified as un- 
discovered. 

10. Locally, limited quantities of materials may 
be produced, even though economic analysis has in- 
dicated that the deposit would be too thin, too low 
grade, or too deep to be classified as a reserve. This 
situation might arise when the production facilities 
are already established or when favorable local cir- 
cumstances make it possible to produce material 
that elsewhere could not be extracted profitably. 
Where such production is taking place, the quanti- 
ty of in-place material shall be included in the 
reserve base, and the quantity that is potentially 
producible shall be included as a reserve. The 
profitable production of such materials locally, 
however, should not be used as a rationale in other 



46 



DIVISION OF MINES AND GEOLOGY 



SR 146 



areas for classifying as reserves, those materials 
that are similar in thickness, quality, and depth. 

11. Resources classified as reserves must be con- 
sidered economically producible at the time of 
classification. Conversely, material not currently 
producible at a profit cannot be classified as 
reserves. There are situations, however, in which 
mining plans are being made, lands are being ac- 
quired, or mines and plants are being constructed 
to produce materials that do not meet economic 
criteria for reserve classification under current 
costs and prices, but would do so under reasonable 
future expectations. For some other materials, 
economic producibility is uncertain only for lack of 
detailed engineering assessment. The marginal- 
reserves category applies to both situations. When 
economic production appears certain for all or 
some of a marginal reserve, it will be reclassified as 
reserves. 

12. Materials that are too low grade or for other 
reasons are not considered potentially economic, in 
the same sense as the defined resource, may be 
recognized and their magnitude estimated, but 
they are not classified as resources. A separate 
category, labeled other occurrences, is included in 
figures 1 and 2. 

13. In figure 1, the boundary between subeco- 
nomic and other occurrences is limited by the con- 
cept of current or potential feasibility of economic 
production, which is required by the definition of a 
resource. The boundary is obviously uncertain, but 
limits may be specified in terms of grade, quality, 
thickness, depth, percent extractable, or other 
economic-feasibility variables. 

14. Varieties of mineral or energy commodities, 



such as bituminous coal as distinct from lignite, 
may be separately quantified when they have 
different characteristics or uses. 

15. The amount of past cumulative production is 
not, by definition, a part of the resource. Never- 
theless, a knowledge of what has been produced is 
important to an understanding of current re- 
sources, in terms of both the amount of past pro- 
duction and the amount of residual or remaining 
in-place resource. A separate space for cumulative 
production is shown in figure 1. Residual material 
left in the ground during current or future extrac- 
tion should be recorded in the resource category 
appropriate to its economic-recovery potential. 

16. In classifying reserves and resources, it is 
necessary to recognize that some minerals derive 
their economic viability from their coproduct or 
byproduct relationships with other minerals. Such 
relationships must be clearly explained in foot- 
notes or in an accompanying text. 

17. Considerations other than economic and ge- 
ologic, including legal, regulatory, environmental, 
and political, may restrict or prohibit the use of all 
or part of a deposit. Reserve and resource quan- 
tities known to be restricted should be recorded in 
the appropriate classification category; the quanti- 
ty restricted and the reason for the restriction 
should be noted. 

18. The classification system includes more divi- 
sions than will commonly be reported or for which 
data are available. Where appropriate, divisions 
may be aggregated or omitted. 

19. The data upon which resource estimates are 
based and the methods by which they are derived 
are to be documented and preserved. 



1987 



MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 



47 



RESOURCES OF (commodity name) 
[A part of reserves or any resource category may be restricted from extraction by laws or regulations (see text)] 
AREA: (mine, district, field. State, etc.) UNITS: (tons, barrels, ounces, etc.) 



Cumulative 
Production 



IDENTIFIED RESOURCES 



Demonstrated 



Measured 



Indicated 



Inferred 



UNDISCOVERED RESOURCES 



Hypothetical 



Probability Range 
(or) 



Speculative 



ECONOMIC 



MARGINALLY 
ECONOMIC 



SUB- 
ECONOMIC 



Reserves 



Inferred Reserves 



Marginal Reserves 



Demonstrated 
Subeconomic Resources 



Inferred 
Marginal Reserves 



Inferred 

Subeconomic 

Resources 



+ 



Other 
Occurrences 



Includes nonconventional and low-grade materials 



Author: Date: 

Figure 1.- Major elements of mineral-resource classification, excluding reserve base and inferred reserve base. 

RESOURCES OF (commodity name) 

[A part of reserves or any resource category may be restricted from extraction by laws or regulations (see text)) 
AREA: (mine, district, field. State, etc.) UNITS: (tons, barrels, ounces, etc.) 



Cumulative 
Production 



IDENTIFIED RESOURCES 



Demonstrated 



Measured 



Indicated 



Inferred 



UNDISCOVERED RESOURCES 



Hypothetical 



Probability Range 
(orF 



Speculative 



ECONOMIC 



MARGINALLY 
ECONOMIC 



SUB- 
ECONOMIC 



Reserve 



Base 



Inferred 



Reserve 



Base 



+ 



Other 
Occurrences 



Author: 



Includes nonconventional and low-grade materials 



Date: 

Figure 2. -Reserve base and inferred reserve base classification categories. 

* U.S. GOVERNMENT PRINTING OFFICE: 1980 O- 311-344/106 



APPENDIX B 

Summary Of The Classification Of MRZ-3 Areas, 
Construction Materials Only 



1987 MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 51 



AREAS CLASSIFIED MRZ-3 



A. MARIN COUNTY: 

Plate 3.5 Bolinas Quadrangle 

MRZ-3 

(a) Franciscan Complex greenstone — Similar material is being quarried and crushed for aggregate in the Bay area. 
This deposit is classified MRZ-3 because of lack of underground data and information regarding suitability of rock 
for aggregate. Only known use for greenstone in the quadrangle is for fill. 

Plate 3.8 Novato Quadrangle 

MRZ-3 

(a) Sonoma Volcanics andesite — Andesite and basalt from the Sonoma Volcanics has been quarried and crushed for 
use as aggregate a few miles to the north. The possible existence of tuff breccia in the deposit may make the andesite 
unsuitable for aggregate other than fill. 

(b) Franciscan Complex greenstone — The material may be suitable for aggregate, but the bodies of greenstone may 
be too small to meet threshold values needed for a MRZ-2 classification. 

(c) Franciscan Complex sandstone and shale — Some local deposits of sandstone suitable for aggregate probably occur 
within the one or more areas classified MRZ-3. The interbedded shale is unsuitable for aggregate. The area is 
classified MRZ-3 because available geologic mapping does not delineate between masses of sandstone and shale. 

Plate 3.9 Petaluma Point Quadrangle 

MRZ-3 

(a) Novato Conglomerate — These two small areas have been classified MRZ-3 because there may be insufficient 
material present to meet threshold value. 

(b) Franciscan Complex sandstone and shale — Sandstone suitable for aggregate is interbedded with shale, which is 
suitable only for fill. Available geologic mapping does not delineate between sandstone and shale. The area has 
been classified MRZ-3 because of the lack of information on the location of the masses of sandstone. 

Plate 3.10 Petaluma River Quadrangle 

MRZ-3 

(a) Sonoma Volcanics andesite flows — Many small masses of andesite located within Quaternary landslide debris may 
be suitable for aggregate. Data regarding location, size, and extent of these bodies are not available. 

Plate 3. 1 1 Point Bonita Quadrangle 

MRZ-3 

(a) Franciscan Complex chert — This small area is underlain by chert, which has been used for aggregate in the Bay 
area. This is the northern tip of a large deposit which extends to the south. 

Plate 3.12 San Francisco North Quadrangle 

MRZ-3 

(a) Franciscan Complex greenstone — Greenstone has been quarried for aggregate at several locations in Marin 
County. Data regarding degree of weathering and amount of tuff breccia within the greenstone is not available. 

(b) Franciscan Complex chert — Chert suitable for fill and roadbase may be present in one or more of these areas, 
but rock quality data is not available. 

(c) Franciscan Complex metamorphic rocks— These deposits contain material which consists primarily of metavolcan- 
ic rocks with some bodies of metachert. Exposures are small but prominent. Data on rock quality and quantity 
are not available. 

Plate 3.13 San Geronimo Quadrangle 

MRZ-3 

(a) Franciscan Complex greenstone — Similar material is being quarried and used for aggregate in the Bay area. Data 
regarding suitability of the greenstone at these two localities are not available. 

(b) Franciscan Complex sandstone and shale — Several areas are underlain by thickly bedded sandstone and interbed- 
ded shale. Similar material is being quarried for aggregate in Marin County. The areas are classified MRZ-3 
because of the lack of available detailed geologic mapping delineating masses of sandstone from shale bodies. 



52 DIVISION OF MINES AND GEOLOGY SR 146 



Plate 3.14 San Quentin Quadrangle 

MRZ-3 

(a) Franciscan Complex metamorphic rocks — Some local bodies of rock (metamorphosed graywacke, greenstone, and 
metachert) suitable for aggregate undoubtedly exist within the areas, but because of the lack of information 
regarding exact location and size of the deposits, the areas are classified MRZ-3. 

(b) Franciscan Complex sandstone and shale — Several areas underlain by sandstone and shale have been classified 
MRZ-3 because available geologic maps do not delineate between sandstone and shale. The shale is not suitable 
for aggregate (except for fill). Similar sandstone is being quarried for aggregate elsewhere in Marin County. 

Plate 3.15 San Rafael Quadrangle 

MRZ-3 

(a) Franciscan Complex greenstone — Although similar material has been quarried for aggregate elsewhere in the Bay 
area, greenstone from the San Rafael Quadrangle has not been used. The areas are classified MRZ-3 because of 
the lack of subsurface data and rock quality data. 

(b) Franciscan Complex chert — A quarry at the southwestern end of the area previously was worked for aggregate. 
The area has been classified MRZ-3 because of the possibility that there may not be enough material present to 
meet threshold value. Also, the deposit is structurally complex, with irregular distribution of other rock types with 
the chert. 

(c) Franciscan Complex sandstone and shale — An inactive quarry is located within one of the areas classified MRZ-3. 
The inactive quarry produced dimension stone and aggregate. The areas are classified MRZ-3 because of the lack 
of data concerning quality and extent of material suitable for aggregate. 

B. NAPA COUNTY: 

Plate 3.16 Cordelia Quadrangle 

MRZ-3 

(a) Sonoma Volcanics andesite and basalt, and Quaternary landslide debris — This material is similar to that which 
is found within the adjacent MRZ-2(a) area, but quality data for subsurface material is not available. 

(b) Domengine Formation sandstone, shale and clay — Aggregate and specialty sand has been recovered from the 
Domengine Formation elsewhere in the Bay area. Data on quality of material in this deposit is not available. 

(c) Briones Formation sandstone with minor Sonoma Volcanics-Briones Formation sandstone has been quarried for 
aggregate elsewhere in the Bay area, but no quarry sites are known north of the Bay. Quality of the material and 
extent of the deposits are unknown. 

(d) Franciscan Complex sheared shale and graywacke — This is the northern end of a narrow ridge which extends 
northward from theBenicia Quadrangle. Material suitable for aggregate is being quarried in the Benicia Quadran- 
gle. However, rock exposed in several inactive quarries in Napa County appears to be suitable only for fill. Data 
regarding suitability of material from other localities within the MRZ-3 area is unavailable. 

Plate 3.17 Cuttings Wharf Quadrangle 

MRZ-3 

(a) Sonoma Volcanics andesite and basalt flows with Quaternary landslide debris — This material is similar to that 
found within the adjacent MRZ-2(a) area, but data as to suitability of material for use as aggregate and extent 
of deposit is unavailable. 

(b) Domengine Formation sandstone, shale and clay — Sand has been recovered from the Domengine Formation 
elsewhere in the Bay area. Because of the limited size of the areas and lack of quality data, only an MRZ-3 
classification is justified. 

(c) Unnamed Formation of Sims and others (1973) — This unit consists of mudstone, shale, siltstone, and conglomer- 
ate of the Great Valley Sequence, and includes the Oat Hill deposit. Only known use of this material is for fill, 
but it may be suitable for subbase. 

(d) Briones Formation sandstone with minor Sonoma Volcanics — Sandstone of the Briones Formation has been 
quarried for aggregate at a number of sites in the Bay area, but no quarry sites are known north of the Bay. Quality 
of the material and extent of the deposits are unknown. 

Plate 3.18 Mount George Quadrangle 

MRZ-3 

(a) Sonoma Volcanics rhyolite, andesite, basalt, and tuff — This deposit may contain material suitable for aggregate, 
but information concerning quality is not available. 






1987 MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 53 



Plate 3.19 Napa Quadrangle 

MRZ-3 

(a) Sonoma Volcanics andesitic to dacitic plugs or intrusive complex — These deposits include an inactive quarry site, 
but it is not known whether sufficient material remains to reach threshold value. 

(b) Sonoma Volcanics andesite and basalt flows — This area includes two small deposits which probably do not contain 
enough material to meet threshold value. Suitability of the material for aggregate has not been demonstrated. 

(c) Domengine Formation sandstone — This deposit has not been previously quarried, but sand suitable for fill or 
specialty sand may be present. Sand has been recovered from the Domengine Formation elsewhere in the Bay area. 

C. SOLANO COUNTY: 

Plate 3.20 Benicia Quadrangle 

MRZ-3 
(a) Franciscan Complex sheared shale and graywacke — This may be a continuation of the adjacent MRZ-2(a) area, 

but data on quality and subsurface extent are not available. Two inactive quarries located outside of the quadrangle 

contain material suitable only for fill. 

Plate 3.16 Cordelia Quadrangle 

MRZ-3 

(d) Franciscan Complex sheared shale and graywacke — This area is underlain by sheared graywacke and silica- 
carbonate rock. Available data does not justify more than MRZ-3 classification for this area. 

D. SONOMA COUNTY: 

Plate 3.25 Cotati Quadrangle 

MRZ-3 

(a) Sonoma Volcanics basalt, scoria, and tuff — Although two inactive quarries are located in one of these areas, a field 
examination showed that most of the material appears to be suitable only for fill but the rock may be suitable for 
subbase aggregate. No data is available regarding suitability of the rock for aggregate at the other areas given an 
MRZ-3 classification. 

Plate 3.27 Glen Ellen Quadrangle 

MRZ-3 

(a) Sonoma Volcanics andesite and basalt — Several small areas are underlain by volcanic rock. Similar material has 
been quarried elsewhere in the area for use as aggregate. Subsurface data and quality data are not available. 

Plate 3.28 Kenwood Quadrangle 

MRZ-3 

(a) Sonoma Volcanics andesite and basalt — Two areas with several inactive quarry sites contain material similar to 
that which has been used for roadbase and asphaltic concrete aggregate. The deposits may be too small to meet 
threshold value. 

(b) Sonoma Volcanics rhyolite — This deposit is similar to the MRZ-2(a) area, but has not been quarried. Rock quality 
and the extent of suitable aggregate are unknown. 

(c) Sonoma Volcanics andesite and basalt — This material may be suitable for aggregate, but the deposit may be too 
small to meet threshold value. 

Plate 3.29 Petaluma Quadrangle 

MRZ-3 

(a) Sonoma Volcanics andesite and basalt — This is a small deposit that may be suitable for aggregate, but has not been 
previously quarried and may be too small to meet suggested threshold value. 

Plate 3.30 Santa Rosa Quadrangle 

MRZ-3 

(a) Sonoma Volcanics andesite and basalt — Some of these areas were quarried for paving blocks. Tuff and tuff-breccia 
may be present at depth. Lack of underground data precludes an MRZ-2 classification. 

(b) Quaternary stream channel material — These deposits were mined in the past, but may not meet threshold value. 



54 ' DIVISION OF MINES AND GEOLOGY SR 146 



Plate 3.32 Sebastopol Quadrangle 

MRZ-3 

(a) Merced Formation sandstone, conglomerate and siltstone — There may be local accumulations of material suitable 
for some aggregate uses. Data regarding aggregate quality and quantity are not available. There were no known 
commercial operations in the past. 

Plate 3.33 Sonoma Quadrangle 

MRZ-3 

(a) Quaternary alluvium — These areas He adjacent to the Sonoma Creek channel deposits, but lack subsurface data 
needed for an MRZ-2 classification. 

(b) Sonoma Volcanics andesite and basalt — The stone may be suitable for aggregate, but the deposit may be too small 
to reach threshold value. 

(c) Sonoma Volcanics rhyolite with minor tuff — This material may be suitable for roadbase, but there may be 
insufficient material to meet threshold value, and data concerning the quality of the material is lacking. 

Plate 3.36 Asti Quadrangle 

MRZ-3 

(a) Quaternary alluvium — Russian River terraces and flood plains, and alluvial fans. Examination of known sand and 
gravel deposits along the Russian River indicates that the commercial-grade sand and gravel extends outward from 
the river channel into the area overlain by soil of the Yolo series. Water-well logs when available, tend to support 
this observation. The area classified MRZ-3 is essentially that shown on the soil maps as Yolo series soil. Deposits 
of commercial-grade sand and gravel may occur in the area classified MRZ-3, but insufficient drill-hole data is 
available to justify an MRZ-2 classification of the area. Water- well logs or other underground data was not 
examined for this area. 

(b) Franciscan Complex greenstone — Several areas are underlain by Franciscan Complex greenstone that may be 
suitable for aggregate. Greenstone is being quarried and crushed for aggregate elsewhere in the Bay area. Detailed 
surface examination and drill-hole data would be necessary to determine if the greenstone is suitable for aggregate. 

Plate 3.37 Cloverdale Quadrangle 

MRZ-3 

(a) Quaternary alluvium — Russian River terraces and flood plains, and alluvial fans. Examination of known sand and 
gravel deposits along the Russian River indicates that the commercial-grade sand and gravel extends outward from 
the river channel into the area overlain by soil of the Yolo series. Water-well logs when available, tend to support 
this observation. The area classified MRZ-3 is essentially that shown on the soil maps as Yolo series soil. Deposits 
of commercial-grade sand and gravel may occur in the area classified as MRZ-3, but insufficient drill-hole data 
is available to justify an MRZ-2 classification of the area. Water-well logs or other underground data was not 
examined for this area. 

Plate 3.38 Geyserville Quadrangle 

MRZ-3 

(a) Quaternary alluvium — Russian River terraces and flood plains, and alluvial fans. Examination of known sand and 
gravel deposits along the Russian River indicate that the commercial-grade sand and gravel extends outward from 
the river channel into the area overlain by soil of the Yolo series. Water-well logs, when available, tend to support 
this observation. The area classified MRZ-3 is essentially that shown on the soil maps as Yolo series soil. Deposits 
of commercial-grade sand and gravel may occur in the area classified MRZ-3, but insufficient drill-hole data is 
available to justify an MRZ-2 classification of the area. Water-well logs or other underground data was not 
examined for this area. 

(b) Sonoma Volcanics — andesitic to basaltic lava flows. According to available geologic maps this area is underlain 
by andesitic to basaltic lava flows. This deposit has not been previously mined nor has it been tested for suitability 
for use as aggregate. However, similar material is being quarried and crushed for aggegate elsewhere in the North 
San Francisco Bay Region. Because of the uncertainty as to quality and quantity of material suitable for aggregate, 
only an MRZ-3 classification is justified. 

(c) Quaternary alluvium — Dry Creek terraces and flood plains. This area extends outward from the creek channel 
and is overlain by the Yolo series soils. Water-well logs were not obtained for this quadrangle, but water-well logs 
for areas overlain by the Yolo series soils a short distance to the south indicate that commercial-grade sand and 
gravel may underlie some of the MRZ-3 (c) areas. 

Plate 3.39 Guerneville Quadrangle 

MRZ-3 

(a) Quarternary alluvium— Dry Creek terraces and flood plains. This area extends outward from the stream channel 
of Dry Creek into the area overlain by soil of the Yolo series. Examination of the site of former sand and gravel 



1987 MINERAL LAND CLASSIFICATION, SAN FRANCISCO-MONTEREY BAY AREA 55 



operations and available water- well logs tends to support this observation. The area classified MRZ-3(a) is 
essentially that shown on soil maps as Yolo series soil. Deposits of commercial-grade sand and gravel may occur 
within the area classified MRZ-3, but insufficient drill-hole data is available to justify an MRZ-2 classification 
of this area. 

(b) Quaternary alluvium — Russian River terraces and flood plains, and alluvial fans. Examination of known sand and 
gravel deposits along the Russian River indicates that the commercial-grade sand and gravel extends outward from 
the river channel into the area overlain by soil of the Yolo series. Water-well logs when available, tend to support 
this observation. The area classified MRZ-3 is essentially that shown on the soil maps as Yolo series soil. Deposits 
of commercial-grade sand and gravel may occur in the area classified MRZ-3, but insufficient drill-hole data is 
available to justify an MRZ-2 classification of the area. 

Plate 3.40 Healdsburg Quadrangle 

MRZ-3 

(a) Quaternary alluvium — Russian River terraces and flood plains, and alluvial fans. Examination of known sand and 
gravel deposits along the Russian River indicate that the commercial-grade sand and gravel extends outward from 
the river channel into the area overlain by soil of the Yolo series. Water-well logs when available, tend to support 
this observation. The area classified MRZ-3 is essentially that shown on the soil maps as Yolo series soil. Deposits 
of commercial-grade sand and gravel may occur in the area classified MRZ-3, but insufficient drill-hole data is 
available to justify an MRZ-2 classification of the area. However, water-well log data though meager, does tend 
to indicate a possibility of the presence of sand and gravel deposits in the MRZ-1 area west of the boundary between 
the MRZ-3 and MRZ-1 area along Forman Lane. The well logs indicate the possible presence of deposits of sand 
and gravel, but location data for the wells requires a field verification of each well location. This was not done 
during the present study. 

(b) Quaternary alluvium — Dry Creek stream channel and terraces. This area extends outward from the creek channel 
and is overlain by soils of the Yolo series. Water-well data indicates the possible presence of deposits of sand and 
gravel, but insufficient data is available to justify an MRZ-2 classification. 

Plate 3.41 Jimtown Quadrangle 

MRZ-3 

(a) Quaternary alluvium — Russian River terraces and flood plains, and alluvial fans. Examination of known sand and 
gravel deposits along the Russian River indicate that the commercial-grade sand and gravel extends outward from 
the river channel into the area overlain by soil of the Yolo series. Water-well logs when available, tend to support 
this observation. The area classified MRZ-3 is essentially that shown on the soil maps as Yolo series soil. Deposits 
of commercial-grade sand and gravel may occur in the MRZ-3, but insufficent drill-hole data is available to justify 
an MRZ-2 classification of the area. Available water-well logs tend to indicate that commercial-grade sand and 
gravel deposits may be located in the MRZ-3 area. However, distribution of water wells is so erratic that potential 
sand and gravel deposits could not be delineated. 

(b) Franciscan Complex greenstone — Several areas on the east side of Alexander Valley are shown on the geologic 
map to be underlain by greenstone. Greenstone is being quarried elsewhere in the Bay area and crushed for use 
as aggregate. One or more of the areas classified MRZ-3 may contain greenstone suitable for aggregate. The MRZ-3 
area a short distance south is the southwestern extremity of a very large deposit of greenstone. 

(c) Sonoma Volcanics andesitic to basaltic lava flows — Deposits of volcanic rock of the Sonoma Volcanics are being 
quarried at several sites within the north Bay area. One or more of the areas classified MRZ-3 may contain material 
suitable for aggregate. However, a detailed site examination with sampling and laboratory testing of the rock would 
be necessary to determine if the material is suitable for aggregate. 



HI) HI 805 



z 2 



H 

m 


m 

> 


CO 


r 


> 


r 


z 


> 


-n 


z 


x 


c 


> 




z 


c 


o 


r 
> 


CO 


a 


o 


c/; 


o 


T1 



i ;; 



m 

m 

-< 

> 

m 
> 



DIVISION OF MINES AND GEOLOGY 
JAMES F DAVIS, STATE GEOLOGIST 



STATE OF CALIFORNIA— GEORGE DEUKMEJIAN. GOVERNOR 

THE RESOURCES AGENCY— GORDON K. VAN VLECK, SECRETARY 
DEPARTMENT OF CONSERVATION — RANDALL M WARD. DIRECTOR 



EXPLANATION 

Boundary of area classified 

Mineral Resource Zone (MRZ) boundary 

County line 

"" ' ' l ~~ P-C boundary (coincides with county line in part) 

SAND B GRAVEL 



SPECIAL REPORT 146 
PLATE 3.1 

PHYSICAL SCIENCES 
LIBRARY 

UC DAVIS 



BOLINAS 

INVERNESS 

NOVATO 

PETALUMA 

PETALUMA POINT 

PETALUMA RIVER 

POINT BONITA 

SAN FRANCISCO NORTH 

SAN GERONIMO 

SAN QUENTIN 

SAN RAFAEL 



MAP NUMBER 


MRZ PLATE 


SECTOR 




NUMBER 


PLATE NUMBER 


76 


3.5 




64 


3.7 


3.60 


66 


3.8 


3.51 


56 


3.29 




67 


3.9 




57 


3.10 


3.52 


86 


3.11 




87 


3.12 




65 


3.13 




78 


3.14 


3.58 


77 


3.15 






37°52 30 — | 






MINERAL RESOURCE ZONES AND RESOURCE SECTORS 

MARIN COUNTY 
North San Francisco Bay Production -Consumption Region 

BY MC.STINSON, M.W.MANSON AND J.J.PLAPPERT 
1983 
SCALE: 1-125.000 



ASE MAP BY u S GEOLOGICAL SURVE 



DIVISION OF MINES AND GEOLOGY 
JAMES F. DAVIS, STATE GEOLOGIST 



STATE OF CALIFORNIA— GEORGE DEUKMEJIAN, GOVERNOR 

THE RESOURCES AGENCY— GORDON K. VAN VLECK, SECRETARY 
DEPARTMENT OF CONSERVATION— RANDALL M. WARD. DIRECTOR 



TN2<-f 
CZ 



flak 3 



SPECIAL REPORT 146 
PLATE 3.4 




PHYSICAL SCIENCES 
LIBRARY 

UC DAVIS 



DIVISION OF MINES S GEOLOGY 
JAMES F DAVIS, STATE GEOLOGIST 

122°37'3Cr R?w 1 650 0001 FE ET'R 6 W 

-2 , I n.i — - — i — > . < ■ 



STATE OF CALIFORNIA— GEORGE DEUKMEJIAN, GOVERNOR 
THE RESOURCES AGENCY— GORDON K. VAN VLECK. SECRETARY 
DEPARTMENT OF CONSERVATION— RANDALL M. WARD, DIRECTOR 



TwJf 

SPECIAL REPORT 146 >™ 
PLATE 3.2 "53 

PHYSICAL SCIENCES 




^ ; W 




50 Map index number 



See text for definitions and explanations of Mineral Resource 
Zones and Resource Sectors. 





INDEX 


TO 


QUADRANGLES 




QUADRANGLE 


MAP NUMBER 


MRZ PLATE 


SECTOR PLATE 








NUMBER 


NUMBER 


BENICIA 
CORDELIA 
CUTTINGS WHARF 
FAIRFIELD SOUTH 


69 
60 
59 
61 




3.20 
3.16 
3.17 
3.21 


3.54 
3.55 


MARE ISLAND 

MOUNT GEORGE 

NAPA 

PORT CHICAGO 


68 
51 
50 
70 




3.22 
3.18 
3.19 
3.23 


3.56 
3.57 



BASE MAP BY US. GEOLOGICAL SURVEY 



DEUKMEJIAN, GOVERNOR 




-, TW24- 
TODU SCIENCES 




MRZ-4 MRZ-I 

MRZ-3 
(a) 













EXPLANATION 

Drill hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established from data supplied by the Oflice of Planning 
and Research with modifications developed Irom information sup- 
plied by local govemmenl and other sources. 

PRODUCTION-CONSUMPTION REGION 80UNOARY 
(see text for discussion) 

MINERAL RESOURCE ZONE BOUNDARIES 



SAND& GRAVEL 



MRZ-1 


Areas where 


adequate information indicates I 


tat no sig- 






irel deposits are present, or w 






judged that 






MRZ-2 


Areas where 




tat signifi- 






deposits ere present, or where i 






that a high 






MRZ-3 


which cenn* 


mmg mineral deposits the sign 
i be evaluated from available da 


cance ol 


MRZ-rt 


Areas wher 


available information is inadeqi 


ate lor as- 




signmenl to 


any other MRZ zone. 




Seete 


t lor addition 


si explanation of MHZ Symbols. 





MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Mar in County 
By 

Melvin C Stinson, Michael W Manson, and John J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



STATE GEOLOGIST 



STATE OF CALIFORNIA-GEORGE DEUKMEJIAN , GOVERNOR 

[ RESOURCES AGENCY-GORDON K VAN VL 
DEPARTMENT OF CONSERVATION-RAt 



CAMP MEEKER QUADRANGLE 



ARD, DIRECTOR 



SPECIAL REPORl 116 PLATE 5 6 



. 































1 -4& 



| 






MRZ-2-t_J 
(b) 



/ \mRZ-2 

L—r- 1 (c) 







EXPLANATION 

Drill hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established from dala supplied by Hie Office o! Plannini 
and Research wiih modilicaiions developed Irom information sup 
plied bv local government and oiher sources. 



SAND & GRAVEL 




MINERAL RESOURCE ZONE BOUNDARIES 

MflZ-1 Areas where adequaie infotmeiion indicates thai no sig- 
nificant mineral deposits ere present, or where it is 
judged thai little likelihood emsis lor their presence 

MflZ-2 Areas where adequaie information indicates ihei signili- 
' deposits are present, or where it is judged 



high li 



i lor t 



MRZ-3 Areas coniainmg mineral deposils Ihe significance 
which cannot be evaluated Irom available data. 

MRZ-4 Areas whrare availnblo information is inadequate for 
signmenl to any other MRZ zone 

See ie»t lor additional e»plan«tion ol MRZ Symbols. 



Of 



EEKER. CALIF 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Sonoma County 
By 

Melvin C Stinson, Michael W. Manson, and John J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4. SECTION 2761 



N-4. MrC 



STATE OF CAUFORNIA-GEORGE DEUKMEJIAN , GOVERNOR 




INVERNESS QUADRANGLE 
SPECIAL REPORT 146 PLATE 3.7 





















^•MRZ-2 
(a) 














EXPLANATION 




AND^rS^oT^^CL^^E^ ^ 07 T ° Ufl9A ^ION 

end R«S *S SJrtT^ t Uppliad bV ' he °"' Ce °' Plflnnin 9 
i J Z , modifications developed rom information suo 

plied by local government and oiher sources wrmanon sup 



PRODUCTION-CONSUMPTION REGION BOUNDARY 



SAND & GRAVEL 



f MR? 2 



MINERAL RESOURCE ZONE 80UNDARIES 

MRZ-l Areas where adequale -nlormation indicates that no sig- 
nificant mineral deposits ere present, or where it is 
ludged lhat little likelihood exists for their presence 

MRZ-2 Areas where adequate information indicates that signili 
cant mineral deposits are present, or where n is fudged 
that a high likelihood for then presence exists 

MRZ-3 Areas containing mineral deposits the significance of 

...,. ? hlch canno ' b " evaluated trom available data. 

MRZ-i Areas where available information is inadequate lor as- 
signment to any other MRZ zone. 

See text for additional explanation of MRZ Symbols. 



INVERNESS. CALIF. 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Marin County 

By 

Melvin C. Stinson, Michael W. Manson, and John J. Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



STATE OF CALIFORNIA-GEORGE OEUKMEJIAN , GOVERNOR 

THE RESOURCES AGENCY-GOROON K VAN VLECK, SECRETARY FOR RESOURCI 
DEPARTMENT OF CONSERVATIGN-RANOALl M WARD, 




NOVATO OUADRANOLo 




SAND & GRAVEL 




EXPLANATION 



OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 

AND LIMIT OF AREA CLASSIFIED 

Boundaries established Irom data supplied by the Ollice of Planning 

plied by local government and other sources. 

PRODUCTION-CONSUMPTION REGION BOUNDARY 

MINERAL RESOURCE ZONE BOUNDARIES 

MRZ-1 Areas where adequate information indicates that no sig- 
nificant mineral deposits are present, or where it is 
ludged thai little likelihood exists for their presence 

MRZ-2 Areas where adequate information indicates that signifi- 
cant mineral deposits are present, or where it is [udged 
that a high likelihood lor their presence exists. 

MRZ-3 Areas containing mineral deposits the significance of 
which cannoi be evaluated from available data 

MRZ-4 Areas where available information is inadequate for as- 
signment to any other MRZ zone. 



NOVATO. CALIF- 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Marin Counly 

By 

Melvin C. Stinson, Michael W. Manson, and John J- Plappert 

1 982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 






I eCjdlllOnfll •■Mil.lri. 



MK/ '.,'1 In.K 



STATE GEOLOGIS 



STATE OF CALIFORNIA-GEORGE DEUKMEJIAN , GOVERNOR 
DEPARTMENT OF CONSERVATION-RANOALL M WfiRO DIRECTOR 



PETALUMA POINT QUADRANGLE 




SAND& GRAVEL 




EXPLANATION 



OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established f.om data supplied by the Office of Planning 
and Research with modifications developed from information sup- 
plied bv local government and other sources. 

PROOUCTION-CONSUMPTION REGION BOUNDARY 

MINERAL RESOURCE ZONE BOUNDARIES 

MRZ-l Aiees where adequate informanon indicates that no sig- 
nificant mineral deposits are present, or where it is 
lodged thai hnie likelihood twists lor their presence. 

MRZ-2 Areas where adequate information indicates thai signili- 
cant mineral deposits are present, or where it is |udged 
thai a high likelihood for their presence exists. 

MRZ-3 Areas containing mineral deposits the significance of 
which cannot be evaluated from available data 

MRZ-4 Areas where available information is inadequate (or as- 
signment to any other MRZ zone. 



-"«"»™ PETALUMA POINT, CALIF. 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Marin County 
By 

Melvin C. Stinson, Michoel W Manson, and John J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



See lent for additional expler 



1 MRZ Symbols 




STATE OF CALIFORNIA-GEORGE OEUKMEJI AN , GOVERNOR 

: RESOURCES AGENCY-GORDON K VAN VLECK. SECRETARY FOR RESOURCES 
DEPARTMENT OF CONSERVATlON-RANOALL M WARD, DIRECTOR 




PETALUMA RIVER QUADRANGLE 

SPECIAL REPORT 146 PLATE 3 10 




EXPLANATION 

Drill hole 

OUTEfl 90UNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established from data supplied by the Office of Planning 
and Research with modifications developed from information sup- 
plied by local government and other sources 



SAND& GRAVEL 




MINERAL RESOURCE ZONE BOUNDARIES 

MRZ-l Areas where adequate information indicates that no sig- 
nificant mineral deposils are present, or where it is 
judged thai little likelihood emis for their presence 

MRZ-2 Areas where adequate information indicates that signifi 
deposits are present or where it is judged 



MHZ 3 



high li 



nmg mineral deposits the ; 



signrneni to any other MRZ i 



ixplanaiion ol mrz s y m 



.« PETALUMA RIVER, CALIF. 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Marin and Sonoma Counties 

By 

Melvin C. Stinson, Michael W. Manson, and John J. Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



E GEOLOGIST MARCH 



STATE OF CALIFORNIA-GEORGE DEUKMEJ1AN , GOVERNOR 

DEPARTMENT OF CONSERVATION-RANDALL M. WARO, OIRECTl 



\ ' \ ■ 
\ \ 



w*% 







W 









\ 










EXPLANATION 



OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established from data supplied by the Olhee of Planning 
and Research with modi heat ions developed from intotmaiion sup- 
plied by local government and other sources 

PRODUCTION-CONSUMPTION REGION BOUNDARY 



SAND & GRAVEL 




MINERAL RESOURCE ZONE BOUNDARIES 

MRZ-1 Areas where adequate information indicates that no 
nificeni mineral deposits are present, or where > 
ludged that little likelihood exists for their presence 

MRZ-2 Areas where adequate information indicates that sig 



MRZ-3 Are 
MflZ-4 Are 



■ .,-. . 



ning mineral deposits the significance Of 



ixplanet.on of MRZ Symbols 



POINT BONITA, CALIF 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Marin County 
By 

Melvin C Stlnson, Michael W. Manson, and Juhn J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 

S// \ 



STATE GEOLOGIS 




SAND & GRAVEL 




EXPLANATION 

Drill hole 

outer BOUNDARY OF areas SUBJECT TO URBANIZATION 

AND LIMIT OF AREA CLASSIFIED 

Boundaries established Irom data supplied by the Ollice ol Planmni 

PRODUCTION-CONSUMPTION REGION BOUNDARY 

MINERAL RESOURCE ZONE BOUNDARIES 

Areas where adequate information indicates lhal no sig- 



■naiiofi is inadequate 
if MRZ Symbols 



SAN FRANCISCO NORTH, CALIF 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Marin County 



Melvin C Slinson, Michael W. Manson, and John J Plapperl 
1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



i ty-<"fc tt/y^*> 



STATE OF CALIFORNIA-GEORGE OEUKMEJIAN , GOVERNOR 

DEPARTMENT OF CONSERVATlON-RANOALL M WARD, DIRECTOR 




SAN GERONIMO QUADRANGLE 
SPECIAL REPORT 146 PLATE 3.13 







MRZ-3 
(a) 



MRZ- 1 
MRZ-4 MRZ-3(b) 




SAND & GRAVEL 




EXPLANATION 

Onll hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established Irom data supplied by the Office of Planning 
and Research with modifications developed Irom information sup- 
plied by local government and other sources. 

PROOUCTION-CONSUMPTION REGION BOUNOARY 
{see text for discussion) 

MINERAL RESOURCE ZONE BOUNOARIES 

MRZ-1 Areas where adequate information indicates that no sig- 
nificant mineral deposits are present, or where it is 
judged that little likelihood exists lor their presence, 

MRZ-2 Areas where adequate information indicates that signifi- 
cant mineral deposits are present, or where it is judged 



MRZ-3 Areas 
MRZ4 Areas 



high li 



ral deposits the sigmficam 
101 oe evaluated Irom available data, 
re available information is inadequate f> 
oany other MRZ ione 



SAN GERONIMO. CALIF. 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Marin County 
By 

Melvin C. Stinson, Michael W. Manson, and John J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



See text lc additional explanation ol MRZ Symbols 



•h^it 




STATi; OF CALIFORNIA-GEORGE DEUKMEJIAN , GOVERNOR 

01 " *TMENT OF CONSERVATION-RANDALL M. WARD, DIRECTOR 




EXPLANATION 



Dull hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established liom deta supplied by the Ollice of Planning 
end Research with modifications developed from information sup- 
plied by local government and other sources. 



MINERAL RESOURCE ZONE BOUNDARIES 



SAND & GRAVEL 














adequate information indicates that no 








eral deposits are present, or where i 






judged thai 


little likelihood exists lor their presence 




MRZ-2 


Areas wher 


adequate information indicates that sigr 


t ::: im±-? ::: j 




that a high 


deposits are present, or where it is judi 


V / s 


MRZ-3 




ming mineral deposits the significance 
SI be evaluated from available data 




MRZ-4 




available information is inadequate for 


STONE 




signment to 


any other MRZ zone 




See.e 


t for addmor 


el explanation of MRZ Symbols. 



SAN QUENTIN, CALIF 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Mann County 

By 

Melvin C. Stinson, Michael W. Manson, and John J. Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



STATE GEOLOGIS 



STATE OF CALIFORNIA-GEORGE DEUKMEJIAN , GOVERNOR 

0EP6RTMENT OF CONSERVATION-R 



SAN RAFAEL QUADRANO 





EXPLANATION 



PRODUCTION-CONSUMPTION REGION BOUNDARY 



SAND & GRAVEL 




MINERAL RESOURCE ZONE BOUNDARIES 

MRZ-i Areas wheie adequate information indicates that no sig- 
nificant mineral deposits are piesent. of where it ts 
ludged that little likelihood exists lor then presence. 

MRZ-2 Areas where adequate information indicates that signifi- 
cant mineral deposits ere present, or where it is |udged 
that g high likelihood lor their presence exists. 

MRZ-3 Aieas containing mineral deposits the significance of 
which cannot be evaluated horn available data. 

MftZ-4 Areas where available information is inadequate (or as- 
signment to any other MRZ zone 



See text lor a 



xplanation ol MRZ Symbols. 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Marin County 

By 

Melvin C. Stinson, Michael W. Manson, and John J. Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 

-Mfa iv-4. tvr*° 

//"STATE GEOLOGIST MARCH I, 1983 




STATE OF CALtFORNlA-SEORGE DEUKMEJIAN , GOVERNOR 



CORDELIA QUADRANGLE 
SPECIAL REPORT 146 PLATE 5 16 




EXPLANATION 



OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established from data supplied t>v the Ollice Of Planning 
and Research wilh modifications developed from information sup- 
plied by local government and other sources 

PRODUCTION-CONSUMPTION REGION BOUNDARY 
{see lext lor discussion) 

MINERAL RESOURCE ZONE BOUNDARIES 



SAND & GRAVEL 




MRZ-I Areas where adequate information indicates that no sig- 
nificant mineral deposits are piesent. 0' where it is 
ludged that little likelihood exists for their presence 

MRZ-2 Areas where adequate information indicates that signifi- 
cant mineral deposits are present, or where it is judged 
that a high likelihood for iheu presence exists. 

MRZ-3 Areas containing mineral deposits the significance of 
which cannot be evaluated from available data, 

MRZ4 Areas where available inlormation is inadequate for as- 
signment to any other MRZ zone. 

See text fot additional explanation of MRZ Symbols. 



CORDELIA, CALIF. 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Napa and Solano Counties 
By 
Melvin C. Stinson, Michael W. Manson, and John J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



H/r-t° 



I 




EXPLANATION 



Drill hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established Irom dale supplied by the Olhce of Planning 
and Resee»ch wiih modifications developed Irom information sup- 
plied by local government and other sources 



MINERAL RESOURCE ZONE BOUNDARIES 



SAND & GRAVEL 




r where i 



MR2-1 Areas where adequate informal! 
nificant mineral deposits are i 
judged thai little likelihood exisi 

MRZ-2 Areas where adequate information indicates thai signifi- 
cant mineral deposits ere present, or where il is fudged 

MRZ-3 Areas containing mineral deposits the significance Of 

MRZ-4 Areas Where available information is inndHrjuate lor as- 
signment 10 any other MR2 /one 

-,>:<■ i.-/i lot arfrJiliorial explAriaiiori ol MR/ Symbols 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Napa and Solano Counties 

By 

Melvin C Stinson, Michael W, Manson, and John J- Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 

" •'Ml fair- 4. H/-M*> 




STATE OF CALIFORNIA-GEORGE DEUKMEJI AN , GOVERNOR 

: RESOURCES AGENCY-GOROON K VAN VLECK. SECRET/1 
ONSERVATION-RANDALL M WAR 



MT. GEORGE QUADRANGLE 
REPORT 146 PLATE 3 IG 




/ — \ r — 



EXPLANATION 



OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established from dale supplied by the Office of Planning 
and Research with modifications developed from information sup- 
plied by local government and other sources. 

PRODUCTION-CONSUMPTION REGION BOUNDARY 



SAND & GRAVEL 



MINERAL RESOURCE ZONE BOUNDARIES 

MR2-1 Areas where adequate information indie 
mficant mineral deposits are present, 
judged that little likelihood exists for lb 

MRZ-2 Areas where adequate information indie 

cam mineral deposits are present, or where it is judged 
that a high likelihood for (heir presence exists. 

MRZ-3 Areas containing mineral deposits the significance of 

MRZ-4 Areas where avertable information is inadequate for as- 
signment to any other MRZ zone. 



MT GEORGE. CALIF. 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Napa and Solano Counties 

By 

Melvin C. Slinson, Michael W. Manson, and John J. Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4. SECTION 2761 



I (org 



nplu 



I MflZ Symbols 



/// 



TATE GEOLOGIST 



P!/y~t*> 



DIVISION OF MINES 







EXPLANATION 

Dnil hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
ANO LIMIT OF AREA CLASSIFIED 

Boundaries established from data supplied by the Of I ice of Planning 
and Research with modifications developed from information sup- 
plied by local government and other sources. 

PRODUCTION-CONSUMPTION REGION BOUNDARY 
(see text for discussion) 

MINERAL RESOURCE ZONE BOUNDARIES 



SAND & GRAVEL 




MRZ-1 Areas where adequate inforn 

ludged that little likelihood e 
MRZ-2 Areas where adequate inlorn 



i indicates that no sig- 



i indicates thai signili- 
or where it is |udged 



MflZ-3 Are 

MRZ4 Are 



information is inadequate lor , 



ixplanation of MHZ Symbols 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Napa County 
By 

Melvin C. Stinson, Michael W- Manson, and John J. Plappert 
1 982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 

rwj ftn~t° 



ST6TE GEOLOGIS 




X 



EXPLANATION 



OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIEO 

Boundaries established Irom data supplied by ihe Olhce ol Planning 
and Research with modifications developed from information sup- 
plied bv local government and other sources 

PRODUCTION-CONSUMPTION REGION BOUNDARY 



SAND & GRAVEL 



V J MRZ-3 Ai 



MINERAL RESOURCE ZONE BOUNDARIES 

MRZ-1 Areas where adequate information indicates that no s 
nificanl mineral deposits are present, or where it 
judged that little livelihood exists for their presence 

MRZ-2 Areas where adequate information indicates that sign 

leir presence exists, 
deposits the significance 
which cannot be evaluated from available data 
MRZ-4 Areas where available information is inadequate for 



V other MHZ 2 
il explanation ol MRZ Symbols 



BENIC1A. CALIF. 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Solano County 
By 

Melvin C Stinson, Michael W Manson, and John J Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 

7^-4. cvr-t° 




SAND& GRAVEL 




EXPLANATION 

Drill hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIEO 

Boundaries established from data supplied bv the Office of Planning 
end Research with modifications developed from informalion sup- 
plied by local government and other sources, 

PROOUCTION-CONSUMPTION REGION BOUNDARY 



MINERAL RESOURCE ZONE BOUNDARIES 

MRZ-1 Areas where adequate information indicates that no sig- 
nificant mineral deposits are present, of where il is 
ludged (hat little likelihood ousts for their presence. 

MRZ-2 Areas where adequate information indicates that signifi- 
cant mineral deposits are present, or where it is judged 
that e high likelihood for their presence exists. 

MRZ-3 Areas containing mineral deposits the significance Of 
which cannot be evaluated Ifom available data. 

MRZ-4 Areas where available information is inadequate tor as- 
signment to any other MRZ zone. 



FAIRFIELD SOUTH, CALIF 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Solano County 

By 

Melvin C.Stinson, Michael W. Manson, ond John J. Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



H/rixi 



See leal for additl 



i»plBi 



.I MHZ Symbols 




EXPLANATION 



SAND & GRAVEL 




OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFfEO 

Boundaries established from dale supplied by the Office of Planning 
and Research with modifications developed from information sup 
phed by local government and other sources 

PRODUCTION-CONSUMPTION REGION BOUNDARY 
(see text for discussion) 

MINERAL RESOURCE ZONE BOUNDARIES 

MRZ-1 Areas where adequate information indicates thai no sig- 
nificant mineral deposits are present. Of where it is 
ludged that little likelihood exists lor their presence 

MRZ-2 Areas wher lequalf. inloimonori md tes that signiii- 

can! mineral deposits are present, or where it is judged 
thai a high likelihood (Of their presence exists. 

MRZ-3 Areas containing mineral deposits the significance of 
which cannr.i bn •■■:,, \-,„u.n tm.n ,iv,j,l„ble data 

MRZ^l Areas where available mlo.ma.ion is inadequate (or as- 
signment 10 Bny other MRZ lone 

See text lor additional explanation of MRZ Symbols. 



MARE ISLAND. CALIF 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Solano County 

By 

Melvin C. Stinson, Michael W. Manson, and John J Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 

■M? 



£ GEOLOGIST 




STATE OF CALIFORNIA-GEORGE OEUKMEJI AN , GOVERNOR 

THE RESOURCES AGENCY-CORDON K VAN VLECK, SECRETARY FOR RESOW 
DEPARTMENT OF CONSERVATlON-HANOALL M. WARD, DIRECTOR 



PORT CHICAGO QUADRANGLE 
>ECIAL REPORT 146 PLATE 3 23 




EXPLANATION 



Drill hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
ANO LIMIT OF AREA CLASSIFIED 

Boundaries established Irom dBta supplied bv Ihe Ollice ol Planning 
and Research with modilicalions developed Irom information sup- 
plied by local government and other sources. 

PRODUCTION-CONSUMPTION REGION BOUNOARY 



SAND & GRAVEL 




MINERAL RESOURCE ZONE BOUNDARIES 

MR.Z-1 Areas where adequate information indicates that no sig- 
nificant mineral deposits are present, or where il is 
judged (hat little likelihood exists lor their presence. 

MRZ-3 Areas where adequale information indicates thai signifi- 
cant mineral deposits aie present, or where il is judged 
Ihai a high likelihood lor their presence exists. 

MRZ-3 Areas containing mineral deposits Ihe significance ol 
which cannot be evaluated Irom available dale 

MflZ-4 Areas where available information is inadequate lor as- 
signment to any othet MRZ zone 

See tent for additional explanation of MRZ Symbols 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Sonoma County 

By 

Melvin C. Stinson, Michael W. Manson, and John J. Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 
/I 



STATE GEOLOGIS 



r 



STATE OK CALIFORNIA-GEORGE OEUKMEJI AN , GOVERNOR 




9 



«■> 



<> 



BODEGA HEAD, CALIF 



SAND & GRAVEL 



EXPLANATION 



OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established from data supplied by the Office of Planning 
end Research wuh modifications developed from information sup- 



PRODUCTION-CONSUMPTION REGION BOUNDARY 
{see text lor discussion) 

MINERAL RESOURCE ZONE BOUNDARIES 



judged that little likelihood exists for their present 1 

MRZ-2 Araes where adequate information indicates lhal s 

cent mineral deposits are present, or where it is |L 

that a high likelihood lor their presence exists 

MRZ 3 Areas containing mineral deposits the significam 

MffZ-4 Areas where available information is inadequate f> 
stgnment lo any other MRZ zone 

explanahon ol MRZ Symbols 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Sonoma County 

By 

Meluin C Stinson, Michael W. Manson, and John J. Plapperl 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



STATE GEOLOGIST 



STATE OF CALIFORNIA-GEORGE DEUKMEJI AN , GOVERNOR 

E RESOURCES AGENCY-GORDON K VAN VLECK, SECRETARY FOR RESOURCI 
DEPARTMENT OF CONSERVATlON-RANOALL M WARD, DIRECTOR 




COTATI QUADRANGLE 

Al REPORT 146 PLATE 3.25 







EXPLANATION 

Drill hole 

OUTER BOUNOARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established from data supplied by the Office of Planning 
and Research with modifications developed from information sup- 
plied by local government and other sources 

PRODUCTION-CONSUMPTION REGION BOUNDARY 
(see text for discussion) 

MINERAL RESOURCE ZONE BOUNDARIES 



SAND & GRAVEL 






MRZ-l Areas where adequate information indicates thai no sig- 




nificant mineral deposits are present, or where it is 




judged that little likelihood e»ists for their presence 




MftZ-2 Areas where adequate information indicates that signifi- 


( (vTR?-2 A 


cant mineral deposits ere present, or where «t is judged 
that a high likelihood for their presence exists. 


\ y 


MRZ-J Areas containing mineral deposits the significance of 



signment lo any other MRZ zone 

for additional explanation ol MRZ Symbols 



COTATI, CALIF. 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Sonoma County 
By 

Melvin C. Stinson, Michael W. Manson, and John J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



tt/7~l*> 



£ GEOLOGIST 



STATE OF CALIFORNIA-GEORGE OEUKMEJI AN, GOVERNOR 




DUNCANS MILLS QUADRANGLE 



MRZ-2 
(a) 



/>" 













\ 








DUNCANS MILLS. CALIF 



EXPLANATION 

Drill hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established from deta supplied by the Olf.ce ol Planning 
and Research with modifications developed Irom information sup- 
plied by local government and othet sources. 



MINERAL RESOURCE ZONE BOUNDARIES 



iANO & GRAVEL 








MRZ-l Areas where adequate inlormetion indicates tl 












judged that little likelihood exists for their pre 






MRZ-2 Areas where adequate information indicates tl 




-'MrW'^ 


cant mineral deposits are present, or where it 
thai a high likelihood lor their presence exists 


s judged 




MRZ-3 Areas containing mineral deposits the signil 


cance of 




MRZ-4 Areas where available information is inadeque 


te for as- 



signment lo any other MRZ zone. 
See text for additional explanation of MRZ Symbols 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Sonoma County 

By 

Melvin C. Stinson, Michael W. Manson, and John J- Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



STATE GEOLOGIST 




SAND& GRAVEL 




EXPLANATION 

Drill hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
ANO LIMIT OF AREA CLASSIFIED 

Boundaries established Irom date supplied by the Office ol Planning 
and Research with modifications developed Irom information sup- 
plied by local government end other sources. 



MINERAL RESOURCE ZONE BOUNDARIES 

MRZ-1 Areas where adequate information indicates thai no sig- 
nificant mineral deposits are present, or where ii is 
judged thai little likelihood exists lor their presence. 

MRZ-2 Areas where adequate information indicates that signifi- 
cant mineral deposits are present, or where it is judged 
that a high likelihood lor their presence exists. 

MRZ-3 Areas containing mineral deposits the significance ol 
which cannot be evaluated from available data 

MRZ-4 Areas where available information is inadequate lor as- 
signment to any other MBZ zone. 

See text lor additional explananon ol MRZ Symbols. 



GLEN ELLEN, CALIF. 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Sonoma County 
By 
Melvin C Stinson, Michael W. Manson, and John J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 






TATE GEOLOGIST 



STATE OF CALIFORNIA-GEORGE DEUKMEJI AN , GOVERNOR 



i, STATE GEOLOGIST 



'■ ! ":" . ;,.'.- . .'•: i- - 




KENWOOD QUADRANGLE 



-", '2 ■ 







EXPLANATION 



Boundaries established from data supplied by The Office ot Planning 
and Research with modifications developed from inlcmation sup- 
plied by local government and other sources. 

PRODUCTION-CONSUMPTION REGION BOUNDARY 



>n) 



MINERAL RESOURCE ZONE BOUNDARIES 



SAND & GRAVEL 




MRZ-3 Areas c 
MRZ-4 Areas v. 



deposits are presem. or where it is judged 
telihood for their presence exists, 
rung mineral deposits (he significance ol 
t be evaluated from available data 
available information is inadequate for as- 
)ny other MR2 zone 

il explanation of MHZ Symbols. 



KENWOOD. CALIF. 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Sonoma County 

By 

Melvin C. Stinson, Michael W. Manson, and John J. Ploppert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 








L m r 



. ■'.{ ', w» ■ ■ 



•■: 




IL 



EXPLANATION 



OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

ad from data supplied by the Ollice of Planning 



SAND & GRAVEL 




MINERAL RESOURCE ZONE BOUNDARIES 

MRZ-1 Areas where adequate information ini 
mficant mineral deposits are presei 
judged :het little likelihood exists lor 

MRZ-2 Areas where adequate informs 

cant mineral deposits are present, or where it is judged 
thai a high likelihood lot their presence exists. 

MRZ-3 Areas conlatning mineial deposits the significance ol 
which cannot be evaluated Irom available data 

MRZ-4 Areas where available inlormaiion is inadequate lor as- 
signment lo any oiher MRZ zone 

See 10*1 for additional explanation of MRZ Symbols 



PETALUMA. CALIF 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Sonoma County 

By 

Melvin C Stinson, Michael W. Manson, and John J. Plapperl 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 
/I 

GEOLOGIST MARCH I. I9BJ 





STATE OF CALIFORNIA-GEORGE DEUKME JIAN, GOVERNOR 

rM£ RESOURCES AGENCT-GORD0N K VAN VLECK, SECRETAR' 
DEPARTMENT OF C( 



SANTA ROSA QUADRANGLE 



REPORT 146 PLATE 3.30 




=JL 



SAND & GRAVEL 




EXPLANATION 



OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established Irom data supplied bv the Office ol Planning 
and Research with modifications developed Irom information sup- 
plied by local government and other sources 

PRODUCTION-CONSUMPTION REGION BOUNDARY 
(see text lo< discussion) 

MINERAL RESOURCE ZONE BOUNDARIES 

MRZ-1 Areas where adequate information indicates that no sig- 
nificant mineral deposits are present, or where it is 
judged that little likelihood exists lor their presence. 

MRZ-2 Areas where adequate information indicates thai signiti- 
I deposits are present, or where il is (udged 



MRZ-3 Are 



high I. 



f their 
nmg mineral deposits the significance ol 



SANTA ROSA. CALIF. 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Sonoma County 

By 

Melvin C. Stinson, Michael W. Manson, and John J. Plappert 

1 982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



MHZ-4 Areas where available information is madequ 
STONE S ign m8 «,0.n V o 1 h.,MRZ ! on. 

See text lor additional explanation ol MHZ Symbols 



mja rr*€< 



STATE GEOLOGIST MARCH I, I! 




STATE OF CALIFORNIA-GEORGE DEUKMEJIAN , GOVERNOR 
RESOURCES AC-ENCT-COftOON K VAN VLECX, SECRETARY FOR RESOURCES 
OEPARTMENT OF CONSERVATION-RANDALL M WARD, DIRECTOR 



SEARS POINT QUADRANGLE 



SPECIAL REPORT 146 PLATE 3.31 




EXPLANATION 

Drill hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established fiom data supplied by Ihe Ollice ol Planning 
end Research with modilicalions developed Irom intormaiion sup- 
plied by local government and olher sources 

PRODUCTION-CONSUMPTION REGION BOUNDARY 



SAND & GRAVEL 




MINERAL RESOURCE ZONE BOUNDARIES 

MRZ 1 Areas where arlm]u,)i<i ifilnmi,>hr>n mdii <ili<s lhal no sig- 
nificant mineral deposits are p<esent. or where it is 
(udged :hat littte likelihood exists lor ilieir presence 

MRZ-2 Areas where adequate inlormalion indicates that signifi- 
cant, mineral deposits are present, or where it is judged 
thai a high likelihood for their presence exists, 

MRZ-3 Areas containing mineral diiposilS' the signil.cance ol 
which cannoi be evaluated Irom available data 

MflZ-4 Areas where au.ul.ihlc mlormation is inadequate tor as- 
signment io any other MRZ zone. 

See lex! for additional explanation ol MRZ Symbols. 



SEARS POINT. CALIF. 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Sonoma County 
By 

MelvinC. Stinson, Michael W. Manson, and John J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION AG OF 1975, ARTICLE 4, SECTION 2761 

n 





STATE OF CALIFORNIA-GEORGE DEUKMEJIAN, GOVERNOR 

3URCES AGENCY-GORDON K VAN VLECK, SECRETARY FOR RESOURCES 
DEPARTMENT OF CONSERVATION-RANDALL M. WARD, DIRECTOR 



SEBASTOPOL QUADRANOLE 
ECIAL REPORT 146 PLATE 3.32 




EXPLANATION 

Dull hole 

OUTEfl BOUNDARY OF AHEAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries esleblished Irom data supplied by the OHice ol Planning 
and Research with modifications developed (torn information sup- 

PRODUCTION-CONSUMPTION REGION BOUNOARY 
{see text lot discussion) 

MINERAL RESOURCE ZONE BOUNDARIES 



SAND & GRAVEL 




MRZ-l Areas where adequate information indicates tl 
niticant mineral deposits are present, or w 
judged that little likelihood exists lor i 

MRZ-2 Areas where adequate inlormation indicates (hat signili 
cant mineial deposits are present, or where it is judged 
Ihat a high likelihood lor their presence exists. 

MRZ-3 Areas containing mineral deposits the signilicance of 
which cannoi be evaluated from available dale. 

MRZ-4 Areas where available information is inadequate lor as- 
signment to any other MRZ zone 

See text for additional explanation of MRZ Symbols. 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Sonoma County 

By 

MelvinC. Stinson, Michael W. Manson, and John J. Plapperl 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 




M. 



ti/y~t# 



STATE GEOLOGIST MARCH I, 



STATE OF CALIFORNIA-GEORGE OEUKMEJ1AN , GOVERNOR 




SONOMA QUADRANGLE 
SPECIAL REPORT 146 PLATE 3.33 




EXPLANATION 



plied by local government and other 



MINERAL RESOURCE ZONE BOUNDARIES 



SAND & GRAVEL 










Atees where adequate information indicates ihat no sig- 










ludged thai Mil* iikunhnod e*ms for their presence 


f \ 


MfiZ-2 


Areas where adequate mlormalion indicates Ihat signifi- 


(-'M&.$ : ■■■-' J 




cant mineral deposits are present, or where it is |udged 

thai a high likelihood (or their presence exists. 

Areas containing mineral deposils the significance of 


\ ^J 


MRZ-3 






which cannot be evaluated from available data 


STONE 




Areas where available information is madeouate lor as- 
signment to any other MRZ zone 




See te> 


t (or additional explanation ol MRZ Symbols. 



SONOMA, CALIF 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Sonoma County 

By 

Melvin C Stinson, Michael W. Manson, and John J. Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 





STEWARTS POINT. laLIK 



EXPLANATION 



OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 

ANO LIMIT OF AREA CLASSIFIED 

Boundaries established t'om data supplied by trie Ollice ol Plannmi 



PRODUCTION CONSUMPTION REGION BOUNDARY 
(see text lor discussionl 

MINERAL RESOURCE ZONE BOUNDARIES 



SAND & GRAVEL 


MRZ-l 


Areas «mer 


•dtw.li mlo.m.tton tndre.t.s M „„ s, S - 


/^TiX 


MBZi 


A, d .'",*h.*' 




( Mfti-2 J 






kelihood loMhe^mesenreTV ' S '"^^ 


\ ___/ 


MBZ3 




mmg mineral deposits the significance ol 


STONE 


MHZ* 


signmenr to 


available information is inadequate loi as- 
any othet MHZ lone 




Seele 


1 lor eddmor 


al oiplanalion ot MHZ Symbols 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Sonoma County 



Melvin C. Stinson, Michael W. Manson, and John J Plappert 
1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



/J . 




EXPLANATION 

Onll hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIEO 

Boundaries established from data supplied by (he Office ol Planning 
and Research with modi heat ions developed from inlormehon sup- 
plied by local government and other sources. 

PROOUCTION-CONSUMPTION REGION BOUNDARY 



SAND & GRAVEL 




MINERAL RESOURCE ZONE BOUNDARIES 

MRZ-1 Areas where adequate information indicates that no sig- 
nificant mineral deposits ate present, or where n is 
ludged that little likelihood exists for then presence. 

MRZ-2 Areas where adequate information indicates thai signifi- 
cant mineral deposits are present or where il is |udged 
lhat a high likelihood lor their presence exists 

MRZ-3 Areas containing mineral deposits the signilicance ol 



MRZ-4 



J from 



I for additional explanation of MRZ Symbols 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Sonoma County 
By 
Melvin C.Stinson, Michael W. Manson, and John J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



STATE OF CALIFORNIA-GEORGE OEUKMEJI AN , GOVERNOR 

OEPARTMENT OF Ci 




ASTI QUADRANGLE 





-vi 




ASTI. CALIF. 



SAND & GRAVEL 




EXPLANATION 



OUTER BOUNOARY Of AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established (torn dele supplied by ihe Oflice ol Planning 
end Research with modilicaiions developed from information sup~ 
plied by locel government and other sources. 

PRODUCTION-CONSUMPTION REGION BOUNDARY 
(see text lor discussion) 

MINERAL RESOURCE ZONE BOUNDARIES 

(here adequate information indicates thet no sig- 
mmeral deposits ere present, or where it is 
judged that little likelihood exisls for their presence. 

vhere adequate informal ion indicatHs ih.'ii signifi- 
cant mineral deposits are present, or where it is judged 
that a high likelihood for their presence exists. 
MRZ-3 Areas containing mineral deposits the significance of 

which cannot be evaluated Irom available data, 
MRZ-4 Areas where available information is medequate for as- 
signment to any other MHZ zone. 

See text (or additional explanation ol MRZ Symbols. 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Sonoma County 
By 

Melvin C.Stinson, Michael W. Manson, and John J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 

RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 

/} /i 




STATE OF CALIFORNIA-GEORGE DEUKMtJIAN , GOVERNOR 



CLOVERDALE OUADRANOLE 




SAND & GRAVEL 




EXPLANATION 

Drill hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established from data supplied by the Office of Planning 
and Research with modifications developed from information sup- 
plied by local government and other sources 

PRODUCTION-CONSUMPTION REGION BOUNDARY 
(see text for discussion) 

MINERAL RESOURCE ZONE BOUNDARIES 

MRZ-1 Areas where adequate information indicates ihat no sig- 

ludged thai little likelihood exists lor their presence. 

MRZ-2 Areas where adequate information indicates that signifi- 
cant mineral deposits are present, or where it is judged 
that a high likelihood lor their presence exists. 

MRZ-3 Areas containing mineral deposits the significance ol 

MRZ-4 Areas where available information is inadequate for as- 
signment to any other MRZ zone. 



CLOVERDALE. CALIF. 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Sonoma County 

By 

Melvin C. Stinson, Michael W, Manson, and John J. Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



Ik to w^tl ivrio 




STATE OF CALIFORNIA-GEORGE OEUKM 

i RESOURCES AGENCf-CORDON K. VAN VLECK, SE> 

OEPAItTMENT OF CONSERVATION 



.GOVERNOR 



GEYSERVILLE QUADRANGLE 




GEYSERVILLE, CALIF. 



EXPLANATION 

Dull hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established from data supplied by the Office of Plannim 
end Research with modifications developed Irom information sup 
plied by It 



PRODUCTION-CONSUMPTION REGION BOUNDARY 



MINERAL RESOURCE ZONE BOUNDARIES 



SAND & GRAVEL 




MRZ-1 Areas * 



likelih 



sfci 



MRZ-3 Ai 
MRZ-4 At 



where adequate infori 
liner a I deposits are present, or wf" 
high, livelihood lor their presence 
containing mineral deposits the 

where available inlorr 
gnmenl to any other MRZ 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Sonoma County 



Melvin C. Stinson, Michael W. Manson, and John J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 
/I 




TATE GEOLOGIST 




STATE OF CALIFORNIA-GEORGE DEUKMEJI AN , GOVERNOR 

: RESOURCES AGENCY-GORDON K VAN VLECK, SECRETARY FOR RESOURCES 

DEPARTMENT OF CONSERVATION-RANDALL M. WARD, DIRECTOR 



GUERNEVILLE QUADRANGLE 



£4 



i^rr^FV'' s 



MRZ-2(c) 



a 




i 1 



MRZ-4-V 






MRZ-I^f 



m 






, ; 






: I 

MRZ-3(b) 

MRZ-4^ 



"fci ; " 



:|.& 



MRZ- 

„. MRZ-4'-* 
MRZ- 2(b) 

"MRZ-4 
"\ MRZ-I 




EXPLANATION 



Drill hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established Irom dale suoplied by Ihe Olhce ol Planning 
and Research wilh modiltcetions developed Irom inlormetlon sup- 
plied by local government and other soutces. 

PRODUCTION-CONSUMPTION REGION BOUNDARY 



MINERAL RESOURCE ZONE BOUNDARIES 



SAND 8 GRAVEL 




MRZ-l Areas where adequate Ir 

nilrcanl mineral deposits ate presenr. or where it is 
judged that little likelihood exists lot their presence 

MRZ-2 Areas where adequate inlotmatton indicates that signifi- 
cant mineral deposits are present, of where It is Iudged 
that a high likelihood for their presence exists. 

MRZ-3 Areas containing mineral deposits the significance ol 

MRZ-4 Areas where available mloirnaiiuti s inadequate lor as- 
signment to any other MRZ zone. 



GUERNEVILLE, CALIF 

MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Sonoma County 
By 
Melvin C.Stinson, Michael W. Manson, and John J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



See text lot a 



jxplanalion ol MRZ Symbols. 



STATE GEOLOGIST 



STATE OF CALIFORNIA-GEORGE OEUKMEJi AN, GOVERNOR 




HEALDSBUR'- QUADRANGLE 




HEALDSBURG, CALIF. 



SAND & GRAVEL 



EXPLANATION 



OUTER BOUNOARt Of- AHHAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established liom data supplied by the 01 1 ire ol Planning 
and Research with modifications developed from information sup- 
plied by local government and other sources 

PRODUCTION-CONSUMPTION REGION BOUNDARY 



MINERAL REViUHf f- /i.NI HnUNf.AHIP. 




ir MRZ zone 
See text lor additional explanation ol MRZ Symbols. 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Sonoma County 
By 

Melvin C. Stinson, Michael W. Manson, ond John J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 

titn^l art" 

.//"STATE GEOLOGIST MARSH I, 1983 



cs# 



JIMTOWN QUADRANGLE 
SPECIAL REPOflT 146 PLATE 3.1 




JIMTOWN, CALIF. 



EXPLANATION 

Drill hole 

OUTER BOUNDARY OF AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established from data supplied by the Office of Planning 
and Research with modifications developed from information sup- 
plied by l< 



PROOUCTION-CONSUMPTION REGION BOUNOARY 
(see text for" discussion) 

MINERAL RESOURCE ZONE BOUNDARIES 



SAND & GRAVEL 




MRZ-1 Areas whe< 


adequate information indicates thai no sig- 




eral deposits are present, or where il is 




little likelihood exists lor their presence 


MRZ-2 Areas wher 


> adequate mformaiion indicates thai signifi- 




deposits are present, of where il is judged 


that a high 




MRZ3 Areas com 


inmg mineral deposits the sigmlicance of 






MRZ-4 Areas wher 


e available mlormalion is inadequate lor as- 


signment tc 


any other MRZ zone 


See text lor addmo 


al explanation of MRZ Symbols. 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 

Sonoma County 

By 

Melvin C Stinson, Michael W Manson, and John J- Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



i^ 



\ Pn wtL H/Trt* 




STATE OF CALIFORNIA-GEORGE DEUKMEJI AN , GOVERNOR 

: RESOURCES AGENCY-GORDON K VAN VLECK, SECRETARY FOR RESOURP 

DEPARTMENT OF CONSERVATION-RANDALL M WARD, OtRECTOR 



MARK WEST SPRINGS QUADRANGLE 



7^1 ~Tv , SJ^V' W ^ '■ "^ 




'• r -' '■'<: 






-■ 





m, 



m 



,1 «*ff 



M ■'*§■■. 




: 



MRZ-2(a) N 



| 

>' 






. 




.te!^M£S 



MARK WEST SPRINGS, CALIF. 



EXPLANATION 

Drill hole 

OUTER BOUNDARY Of AREAS SUBJECT TO URBANIZATION 
AND LIMIT OF AREA CLASSIFIED 

Boundaries established from data supplied by the Ollice ol Planning 
and Research with modifications developed from information sup- 
plied by local government and other sources. 



MINERAL RESOURCE ZONE BOUNDARIES 



SAND & GRAVEL 




MRZ-1 Areas where adaq> 
MRZ-2 A 



kehh 



r iheir presence. 

nditdifes thai sign.li- 

r where it is judged 



ntnoral deposits are 
that e high likelihood lor 
MRZ3 Areas containing mineral deposits Ihe significance ot 

MRZ-4 Areas where available Information is inadequate for as- 
signment to any other MRZ zone. 

See text for additional explanation of MflZ Symbols. 



MINERAL LAND CLASSIFICATION MAP 

AGGREGATE RESOURCES ONLY 
Sonoma and Napa Counties 

By 

Melvin C. Stinson, Michael W. Manson, and John J- Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING AND 
RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 




M. 



?t/r-t*> 






JAMES F DAVIS, STATE G 






STATE OF CALIFORNIA-GEORGE DEUKMEJIAN , GOVERNOR 

! RESOURCES AGENCY-GORDON K VAN VLECK, SECRETORY FOR RESOURCI 

DEPARTMENT OF CONSERVATION-RANDALL M WARD, DIRECTOR 




AST! QUADRANOLE 



• 






SPECIAL REPORT W6 PLATE J 42 
1 



( 







ASTI, CALIF. 




EXPLANATION 

Sector boundary 

Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 



Melvin C. Stinson, Michael W Manson, and John J Plappert 
1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLED, SECTION 2761 



■u< 



Hrt^ 



EMBER 1. 1962 



STATE OF CALIFORNIA-GEORGE OEUKMEJI AN , GOVERNOR 

THE RESOURCES AGENCY-GOROON K VAN VLECK, SECRETARY FOR RESOURC 

DEPARTMENT OF CONSEHVAT.ON-RANOALL M. WARO, QIRECTOR 



CLOVERDALE QUADRANOLE 














EXPLANATION 



Sector boundary 



Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



CLOVERDALE. CALIF. 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 

By 

Melvin C Stinson, Michael W Manson, and John J Plappert 

1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



A?.>ft^i' 




STATE OF CALIFORNIA-GEORGE DEUKMEJIAN , GOVERNOR 

: RESOUBCES AGENCY-GOROON K VAN VLECK, SECRETARY FOR RESOURCI 
DEPARTMENT OF CONSERVATION-RANDALL M WARD, DIRECTOR 



GEYSERV1LLE QUADRANOLE 




GEYSERVILLE. CALIF. 




EXPLANATION 

Sector boundary 

Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 

By 

Melvin C. Stinson, Michael W. Manson, and John J. Plappert 

1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



>/JLfo [y/£ fl/riv 






: 










STATE OF CALIFORNIA-GEORGE DEUKMEJI AN , GOVERNOR 

DEPARTMENT OF CONSERVATION-RANDALL M WARO, DIRECTOR 



« 



- 



JIMTOWN QUADRANGLE^ 
SPECIAL REPORT 146 PLATE 5 4 "5 





JIMTOWN. CALIF 




EXPLANATION 



Sector boundary 



Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 



Melvin C Stinson, Michael W Manson, and John J Plappert 

1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLED, SECTION 2761 



'■MA) t~'L tl/y~t" 



STATE OF'CALIFORNIA-GEORGE DEUKMEJI AN , GOVERNOR 



; ■. j 



" 






...,-q 
















' 





EXPLANATION 

Sector boundary 

Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



GUERNEVILLE. CALIF 



N 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 



Melvin C Stinson, Michael W Manson, and John J Plappert 
1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



J't<b f-"'l art" 

y^TATE 



STATE OF CALIFORNIA-GEORGE OEUKMEJI AN, GOVERNOR 

RESOURCES AGENCY-GORDON K VAN VLECK, SECRETARY FOR RESOURC 

OEPARTMENT OF CONSERVATION-RANDALL M WARD, DIRECTOR 




HEALDSBURO QUADRANGLE 
SPECIAL REPORT 146 PLATE 3.47 




HEALDSBURC. CALIF 




EXPLANATION 



Sector boundary 



Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



N 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 

By 
Melvin C Stinson, Michael W Manson, and John J, Plappert 

1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



f-- '{, ur-lv 




STATE OF CALIFORNIA-GEORGE DEUKMEJIAN , GOVERNOR 

;S AGENCY-GORDON K VAN VLECK, SECRETARY FOR RESOURT 
OEPARTMENT OF CONSERVATION-RANDi 











^i'. . 



GLEN ELLEN. CALIF 




EXPLANATION 



Sector boundary 



Properties owned or 

controlled by aggregate 
producers 

Depleted resources 



N 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 

By 
Meluin C- Stinson, Michael W Manson, and John J. Plappert 

1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLED, SECTION 2761 



N- >''L MrC" 




STATE OF CALIFORNIA-GEORGE DEUKMEJI AN , GOVERNOR 

: RESOURCES AGENCY-GORDON K VAN VLECK, SECRETARY FOR RESOURCES 

DEPARTMENT OF CONSE RVATION-RANOALL M WARD, DIRECTOR 



SEARS POINT QUADRANGLE 



SPECIAL REPOR 



if! 




SEARS POINT. CALIF- 




EXPLANATION 

Sector boundary 

Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



N 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 



Melvin C. Stinson, Michael W Manson, and John J. Plappert 
1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLED, SECTION 2761 



„.-M.<b ?r >'l tor*" 

//^■dTATE GEOLOGIST septembi 



STATE OF CALIFORNIA-GEORGE OEUKMEJI AN , GOVERNOR 



SONOMA QUADRANGLE 



V^ 



1 



M 



! 



SECTOR C-2b 




SECTOR C-4 



SECTOR C-5 










SONOMA. CALIF 




EXPLANATION 



Sector boundar 



Properties owned or 

controlled by aggregate 
producers 

Depleted resources 



N 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 



Melvin C. Stinson, Michael W Manson, and John J. Plappert 
1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



M.'j) f- '4. fUy-t» 



GEOLOGIST SEPTEMBER I, ISB2 




STATE OF CALIFORNIA-GEORGE DEUX ME J I AN , GOVERNOR 

■ RESOURCES AGENCY-GORDON K VAN VLECK, SECRETARY FOR RESOURO 

DEPARTMENT OF CONSERVATION-RANOALL M WARD, DIRECTOR 



NOVATO QUADRANCiLt 

REPORT 145 PLATE 3.51 




TOPOGRAPHIC BASE MAP BT U.S. GEOLOGICAL SURVEY 
Reduced Irom I 24.000 




NOVATO. CALIF 




EXPLANATION 



Sector boundary 



Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



N 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 



Melvin C. Stinson, Michoel W Manson, and John J. Plappert 
1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE4. SECTION 2761 



M. 



tWL tt/rt^ 



STATE GEOLOGIST SEPTEMBl 




STATE OF CALIFORNIA-GEORGE OEUKMEJI AN , GOVERNOR 
; RESOURCES AGENCT-GOR0ON K VAN VLECX, SECRETORY FOR RESOURC 
OEPARTMENT OF CONSERVATION-RANDALL M WARO, DIRECTOR 



PETALUMA RIVER QUADRANOLE 

SPECIAL REPORT I1G PLATE 3.52 




PETALUMA RIVER, CALIF. 




EXPLANATION 



Sector boundary 



Properties owned or 
controlled by aggregate 
producers 

Depleted Resources 



N 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 

By 
Melvin C Stinson, Michael W Manson, and John J Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 

7 



GEOLOGIST SEPTEMBER 




STATE OF CALIFORNIA-GEORGE DEUKMEJI AN, GOVERNOR 

THE RESOURCES AGENCY-GORDON K VAN VLECK, SECRETARY FOR RESOURCES 
DEPARTMENT OF CONSERVATlON-RANOALL M. WAfiO, DIRECTOR 



COTATI QUADRANGLE 
SPECIAL REPORT 146 PLATE 3.53 







COTATI. calif 




EXPLANATION 

Sector boundary 

Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 

By 
Melvin C. Stinson, Michael W Manson, and John J. Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLED, SECTION 2761 




STATE OF CALIFORNIA-GEORGE DEUK ME Jl AN , GOVE RNOR 
OEPftflTMENT OF CONSERVATION-rahoall M WARD, DIRECTOR 




BENICIA QUADRANGLE 



SECTOR G-3 




... f 










BENICIA. CALIF. 




EXPLANATION 



Sector boundary 



Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



N 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 

By 

Melvin C Stinson, Michael W Monson, and John J. Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



■f/ifn iv- /£ a/t~iv 






STATE OF CALIFORNIA-GEORGE DEUKME Jl AN , GOVERNOR 




CUTTINGS WHARF QUADRANGLE 
SPECIAL REPORT 146 PLATE 3,55 









I 




CUTTINGS WHARF. CALIF 




EXPLANATION 

Sector boundary 

Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 



Melvin C. Stinson, Michael W Manson, and John J Plappert 
1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



r^L art" 




STATE OF CALIFORNIA-GEORGE DEUKMEJIAN, GOVERNOR 
DEPARTMENT OF CONSEHVftTlON-RANOALL M. W< 



MT. GEORGE GUADR 





; ■ *•**, 



CVHiiy 










^ 






-SECTOR H 



MT GEORGE. CALIF 




EXPLANATION 

Sector boundary 

Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



N 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 



Melvin C. SJinson, Michael W Manson, and John J. Plappert 
1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



M 



w-r\L m~i*> 



T£ GEOLOGIST SEPTEMBER I, I98Z 





EXPLANATION 

Sector boundary 

Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



NAPA CALIF 

Aggregate Resource Sectors 

North San Francisco Bay P-C Region 

By 

Melvin C. Stinson, Michael W Manson, and John J, Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



JAMES F DAVIS, STATE GEOLOGIS 



STATE OF CALIFORNIA-GEORGE DEUKMEJIAN , GOVERNOR 
DEPARTMENT OF CONSERVATION-RANDALL M WA«0, DIRECTOR 



\4> 






■%r 


















' \ 



\ 




SAN QUENTIN QUADRANGLE 
SPECIAL REPORT 146 PLATE 3 58 










"" \ , ~ A , ' -' 



RiCfl M"N'Ij 









- \. 












R I C H A R D 



J 




EXPLANATION 



Sector boundary 



Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



N 



SAN QUENTIN, CALIF 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 



Melvin C Stinson, Michael W Manson, and John J Plappert 
1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



//"<l^l GEOLOGIST SEPTEMBER 



STATE OF CALIFORNIA-GEORGE OEUKMEJIAN , GOVERNOR 

! RESOURCES AGENCY-GOROON K VAN VLECK. SECRETARY FOR RESOURCI 

DEPARTMENT OF CONSERVATION-RANDALL M WARO, DIRECTOR 



KENWOOD QUA 









KENWOOD, CALIF 




EXPLANATION 

Sector boundary 

Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



N 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 

By 

Melvin C. Stinson, Michael W Manson, and John J. Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 
/} i 

/^"state geologist 



STATE OF CALIFORNIA-GEORGE DEUKMEJIAN , GOVERNOR 

if FOR RESOURCI 
', DIRECTOR 












EXPLANATION 



Sector boundary 



Properties owned or 
controlled by aggregate 
producers 

Depleted resources 









'■'■ 



N 



V x, J 



VERNESS. CALIF 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 

By 

Melvin C Stinson, Michael W Manson, and John J. Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



YA 



1 



'A) kffa tir-c^ 




CAMP MEEKER. CALIF 




EXPLANATION 



Sector boundary 



Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



N 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 
By 

Melvin C, Stinson, Michael W Manson, and John J. Plappert 
1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



r 



AND GEOLOGY 






STATE OF CALIFORNIA-GEORGE DEUKMEJI AN, GOVERNOR 

E RESOURCES AGENCY-CORDON K VAN VLECK, SECRETARY FOR RESOURC' 
OtPARTWENT OF CONSERVATION-RANDALL M WARD, DIRECTOR 




BODEGA HEAD OUADR; 




<P 



BODEGA HEAD. CALIF 




EXPLANATION 



Sector boundary 



Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



N 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 



Melvin C. Stinson, Michael W. Manson, and John J Plappert 
1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 



>KA) 







■' ■ 






V^- SECTOR T 



^ 






'.^:i 






>- * 









,, 





EXPLANATION 



Sector boundary 



Properties owned or 
controlled by aggregate 
producers 

Depleted resources 









Ml 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 

By 

Melvin C Stinson, Michael W. Manson, and John J. Plappert 
1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 

i |y-/fc O/rt*] 



STATE GEOLOGIST sepikmi.ih 




STEWARTS POINT. CALIF 




EXPLANATION 

Sector boundary 

Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 

By 

Melvin C Stinson, Michael W. Manson, and John J. Plappert 

1982 



PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE4, SECTION 2761 



fr^/% ci/yHv 



STATE OF CALIFORNIA-GEORGE DEUKMEJIAN , GOVERNOR 










&1M 



SLiu 



4 



-- + ■' 




MARK WEST SPRINOS QUADRANGLE 



■ V 



L".-:*: 



i 



-r^- 



•'. hSS^f\y « 



fe 












-" 












\ 



; 



— -r, e^r* 




' 




...l i 




&"•*•"' 




MARK WEST SPKINGS, CALIF. 




EXPLANATION 

Sector boundary 

Properties owned or 
controlled by aggregate 
producers 

Depleted resources 



Aggregate Resource Sectors 

North San Francisco Bay P-C Region 

By 

Melvin C Stinson, Michael W Manson, and John J. Plappert 

1982 

PREPARED IN COMPLIANCE WITH THE SURFACE MINING 
AND RECLAMATION ACT OF 1975, ARTICLE 4, SECTION 2761 




THIS BOOK IS DUE ON THE LAST DATE 
STAMPED BELOW 



BOOKS REQUESTED BY ANOTHER BORROWER 
ARE SUBJECT TO RECALL AFTER ONE WEEK. 
RENEWED BOOKS ARE SUBJECT TO 
IMMEDIATE RECALL 



LIBRARY, UNIVERSITY OF CALIFORNIA, DAVIS 

D4613 (12/76) 



11 UNIVERSITY QF 




COLLATE: 



£2 PIECES 





:...,, 






I 



Hm 









: